Everything we hear is an opinion, not a fact.

Everything we see is a perspective, not the truth.

Marcus Aurelius

For every expert there is an equal and opposite expert;

but for every fact there is not necessarily an equal and opposite fact.

Thomas Sowell

4.01  Expert witnesses are a fixture in modern international arbitration.¹ Most sizable cases are dominated by complex questions, such as economic trends in energy markets, the causes of engineering failures, the relationship between obscure biotechnology patents, projected profits, and the like. As the number and range of complex legal questions in transnational disputes have increased, reliance on expert witnesses has also increased. They are now considered essential to decipher and distil various types of information for arbitral tribunals. The consequence of this trend is that expert witnessing in international arbitration is a multi-billion dollar industry for the experts.² It is also an enormous expense for parties.

4.02  Despite the importance of expert witnesses, their ethical obligations have until recently been systematically neglected. In international arbitration, the issue of expert ethics raises many of the same problems analysed in Chapter 2 regarding counsel ethics, but also some unique new ones.³ For example, similar to counsel ethics, there are significant national legal and cultural (p. 140) differences regarding the nature and function of expert witnesses in arbitral proceedings. In some systems, most notably the United States, Australia, and Canada, parties select, compensate, and coordinate with expert witnesses, including communicating with them before they testify.⁴ In many other jurisdictions, such as Germany, France, and the Netherlands, expert witnesses are generally appointed directly by, and function as an ancillary to, the adjudicatory decision-maker.⁵

4.03  When these different national traditions, or expert witness archetypes, are used by opposing parties in a single international arbitration, the problems are obvious. As one commentator posits, perhaps only rhetorically: ‘If one side in the dispute approaches expert witness preparation as an extension of the advocacy process, while the other side adopts notions of impartiality… and the three arbitrators themselves hold to widely different notions of what is proper, is there a level playing field for all participants in the dispute resolution process?’⁶

4.04  Compounding these comparative differences and the fairness concerns that they raise, the ethics of experts are generally not effectively regulated even within individual national legal systems. To put the problem more bluntly, unlike lawyers, most legal systems do not specifically regulate expert witnesses at all. The main reason for this regulatory gap is that expert witnessing is not, in itself, an occupation or profession. Expert witnesses are most often individuals who belong to an established profession (accounting, engineering, etc.). They lend (or more literally rent) their expertise to an adjudicatory process because an issue in dispute is too complex to be fully understood or resolved without expert guidance. Expert witnesses are, however, only ‘moonlighting’⁷ from their primary occupations.⁸

4.05  For these reasons, with a few notable exceptions in England, Australia, and Canada (discussed in greater detail later), experts are not directly regulated by national legal systems when they act as witnesses.⁹ In the absence of formal regulation, the most immediate source of guidance regarding proper conduct of experts is the body that regulates the underlying professions to which they belong. That guidance, however, is necessarily focused on those experts’ performance of the primary tasks of their chosen professions as accountants, engineers, and the like. Only rarely do those professional regulatory bodies aim at regulating their members when they serve as expert witnesses in adjudicatory settings.¹⁰

(p. 141) 4.06  While ethical regulation of expert witnesses is almost non-existent, the costs of unethical expert witnessing can be quite high. Experts are used in an overwhelming majority of cases in both national courts and international arbitrations.¹¹ Experts command high fees, which often represent a substantial expense for parties. In addition, tribunals can expend substantial unnecessary time and effort to sort through unreliable testimony.¹² Even with that extra expenditure, perhaps the most problematic cost is tribunals’ diminished ability to reach accurate substantive conclusions when forced to sort through misleading expert testimony.¹³ For these reasons, the ethical conduct of expert witnesses is a topic that has recently and increasingly captured the attention of international arbitration commentators.

4.07  This chapter surveys the challenges of expert ethics in international arbitration. It begins by examining the comparative differences in the nature and purpose of expert testimony in national legal systems. Although historical practices regarding experts are deeply embedded in particular systems, they also garner significant critiques, both from inside and outside the different systems. Section A surveys these national procedures for expert witnessing, while Section B provides an overview of expert witness practice in international arbitration. Finally, Section C previews the theory of self-regulation, developed more extensively in Chapter 6, through proposed reforms for expert witnesses to be developed by the international arbitration community.

4.08  Chapter 2 explored the cultural differences and ethical regulations that pertain to attorneys when engaging in pre-testimonial communication with witnesses. Several analogous cultural differences manifest themselves in systems’ treatment of expert witnesses. This section examines, in Subsection 1, the national differences in expert witnessing. Subsection 2 examines the criticisms of these various national traditions and some limited reforms that have been introduced to redress them, particularly in England, Australia, Canada, and public international tribunals. The section concludes with some observations about the limits of legal transplants and analyses why some proposed reforms have not taken hold.

4.09  In common law jurisdictions, most notably the United States, experts are selected and paid by the parties. In fact, these witnesses are often described not simply as a ‘party-appointed expert’ or ‘party-selected expert’¹⁴ but as a ‘party’s expert’, with the possessive pronoun (p. 142) linguistically signalling that a party somehow owns the expert, or at least his or her testimony. In some non-trivial way, it is accurate to speak of an ‘ownership’ interest. Expert witnesses are carefully selected based on how well their perspectives, opinions, and (ultimately) conclusions fit with parties’ overall case strategy. Unlike other fact witnesses, ethical rules generally permit attorneys to compensate expert witnesses for their time. Some systems even permit experts to be compensated on a contingency fee basis.¹⁵ While most jurisdictions prohibit such forms of compensation,¹⁶ experts are generally allowed to work closely with counsel and remain intimately involved in case preparation.

4.10  One US commentator offers this explanation of the practical mechanics of experts’ relationships with attorneys:

Litigation is a complex process, and it is important that attorneys be able to communicate with the experts working on the case. The lawyers will invariably have important information, and perhaps suggestions, that will facilitate the experts’ work. Lawyers may also need constant input from the experts as the case proceeds, so that they may adjust their goals and strategies in light of the experts’ findings.¹⁷

Particularly in complex cases, expert testimony is regarded as so essential to parties’ ability to prepare and present their cases that it is treated as an essential procedural right.¹⁸

(p. 143) 4.11  In the US legal system, expert testimony is consistently used in many, if not most, cases, from basic tort cases to employment discrimination cases to complex commercial cases.¹⁹ In criminal²⁰ and mass toxic tort cases—arguably the genres that define the most distinctive qualities of the US legal system—expert testimony plays an especially pivotal role in establishing liability and developing innovative new legal theories.²¹ It would be difficult to overstate the importance of expert testimony in US litigation and to US parties and counsel in developing their case strategy.

4.12  Despite this need for close coordination, however, commentators argue that expert coordination with counsel is ethically legitimate only ‘so long as the relationship remains independent and professional roles are not blurred’.²² The meaning of the term ‘independent’ in this context is by no means self-evident. The term ‘independent’ to describe the obligations of an expert who is unilaterally selected and compensated by only one party, and who works extensively with that party’s counsel, cannot have the same meaning as the requirement that an arbitrator remain ‘independent’ of the parties and their counsel. It also necessarily means something different from the ‘independent’ judgment that attorneys are required to exercise under national ethical rules.²³

4.13  While commentators opine about where the line exists between experts’ professional independence and permissible coordination with lawyers, lawyers in practice publicly and expressly doubt such a line exists. As John C. Shephard, the former president of the American Bar Association explained, ‘I would go into a lawsuit with an objective, (p. 144) uncommitted, independent expert about as willingly as I would occupy a foxhole with a couple of noncombatant soldiers’.²⁴ The academic use of the term ‘independent’ to describe expert witnesses, in other words, contrasts sharply with established practices in the US system.

4.14  While US attorneys are not sure where the line is between assertions of independence and actual practice, in most civil law systems, the entire idea of drawing such a line is an anathema. In systems such as Germany, France, Italy, Turkey, and the Netherlands, experts are most often appointed by the court.²⁵ For instance, in France, Italy, and Hong Kong, the court has exclusive power to appoint experts, usually selected from an approved list and upon party application. Germany, meanwhile, uses a dual system of court-appointed and party-selected experts, but judges are still required to adopt an expert agreed to by the parties or to select an expert from a prescribed list.²⁶

4.15  Experts in civil law jurisdictions are usually obliged, under applicable procedural rules, to be neutral and impartial.²⁷ With court-appointed experts in civil law systems, parties can seek to recuse any expert who is not ‘neutral’, and that standard is interpreted as being as rigorous as related judicial obligations.²⁸ In fact, in Germany, the standards for expert and judicial neutrality derive from the same provisions from the German Code of Civil Procedure.²⁹ Under these regimes, it is simply not permissible for counsel to meet with and coordinate their cases with expert witnesses.

4.16  There are some notable exceptions in which the independence obligations of both judges and experts are less clear. For example, in Brazil, there can be three (or more) expert witnesses, one appointed by the judge and two party-selected experts. Under Brazilian procedures, a judge can communicate with the parties ex parte at any time to ask them questions and can appoint an expert witness, if necessary, to act either separately or in coordination with expert witnesses selected by each of the parties.³⁰

4.17  Even if national traditions regarding expert witnesses are firmly entrenched within particular legal systems, the prevailing common law and civil law traditions are subject to significant criticisms from both inside and outside their home systems. These criticisms have given rise to proposed reforms and important exceptions to the prevailing approaches in both common law and civil law systems. As described in more detail later, some reforms have been successful, but many other reforms have not. This section explores what factors contribute to the success or failure of particular reforms. Building on these observations, Section C of this chapter identifies specific reforms for expert witnesses in international arbitration that it is later proposed in Chapter 6 be adopted as part of a larger project of self-regulation.

4.18  As already described in Chapter 3, the US legal system is probably the most permissive in terms of the nature and extent of contact permitted between lawyers and experts. As a consequence, it is often regarded as the most tolerant of expert witnesses who have partisan dispositions. The criticisms of this tolerance are legion. On the one hand, critics argue that these expert witnesses fail to clarify the issues to be adjudicated because their testimony is tailored to further the client’s case strategy, rather than to provide a full analysis of a given issue.³¹ Relatedly, critics argue that excessively adversarial experts tend to polarize the case, potentially creating conflict and even confusion when in actuality little conflict exists.³²

4.19  Both of these critiques illustrate the basis for yet a third critique—that exaggeration by partisan experts distorts an adjudicator’s decision-making, which in turn creates incentives for experts to exaggerate further. For example, if a respondent’s expert values lost profits at US$5 million and the claimant’s expert at US$10 million, a tribunal might reasonably believe that the true value is around US$7.5 million. The inclination toward splitting the difference between expert conclusions is relatively natural, but it invites potentially exaggerated and unethical contentions from experts.

4.20  For example, if the claimant’s expert opines that the value of lost profits is US$100 million instead of a more reasonable estimate of US$10 million, it would transform the average from US$7.5 million into US$52.5 million. In this respect, compromise outcomes can penalize honest expert estimates and reward improperly exaggerated testimony. A compromise decision is especially problematic when the true value is either very high or very low, for example, in cases when the proper outcome is that there is no liability. This propensity for decision-makers to gravitate toward an average between numbers presented by experts has been documented by empirical and social scientific research into US jury decision-making.³³ It has also been documented among judges and, by extension, arbitrators.³⁴

(p. 146) 4.21  Some reforms have been proposed to resolve these perceived excesses. Most notably, Federal Rule of Evidence 706 was developed to allow for courts to appoint experts.³⁵ The primary purpose of Rule 706 is not to displace party-selected experts, but instead to supplement them. As one commentator explains, the purpose of a court-appointed expert is ‘to enhance the information available to the trier of fact’ and ‘fill in gaps of knowledge necessary for resolution of the parties’ dispute’.³⁶

4.22  Despite this limited role, and urging by several commentators,³⁷ US judges are reticent to use Rule 706 to appoint their own experts.³⁸ Even precautionary measures imposed by the Rule have apparently not been sufficient to overcome judicial concerns.³⁹ Empirical research shows that this reluctance⁴⁰ is a result of ‘uneasiness with court-appointed experts [because of] difficulty in accommodating such experts in a court system that values, and generally anticipates, adversarial presentation of evidence’.⁴¹ Leading scholars advocating for court-appointed experts even concede that this judicial reluctance is ‘understandable’ since judges are products of an adversarial tradition that is deeply ‘ingrained’.⁴²

4.23  Another, even more recent, effort highlights another difficulty in enacting effective reforms. In 2011, the Litigation Section of the American Bar Association (ABA) sought to promulgate Standards of Conduct for Experts Retained by Lawyers (Standards). Although the Litigation Section announced in August 2011 that the Standards had been adopted by the (p. 147) ABA,⁴³ the Standards were abruptly withdrawn to be further revised.⁴⁴ The Standards were revised two more times before being unofficially tabled in August 2012.⁴⁵ A brief look at the adopted-then-retracted Standards reveals both the substantive complexities and the politics in regulating expert witnesses.

4.24  As an initial matter, there are serious doubts about whether the ABA even has the authority to impose standards on experts who act as witnesses. The ABA is a professional organization with indirect authority over the members of one profession—lawyers⁴⁶—but no authority (direct or indirect) over other professions. In an apparent attempt to resolve this jurisdictional problem, the Standards were framed as providing guidance to experts who are ‘retained by lawyers’. Specifically, they stated an aspiration that lawyers incorporate the Standards into their letters retaining experts, so that ‘experts and clients will have a common understanding of what is expected’.⁴⁷ Most objections to expert testimony, however, are not tied to misunderstandings about what is expected. The objections, instead, are that expert witnesses implicitly or explicitly collude to have experts bend their testimony to suit client and attorney expectations.

4.25  Even more importantly, this attempted jurisdictional side-step was itself a profound misstep—technically clients retain experts, not lawyers.⁴⁸ These are only a few of the most obvious problems with the now-withdrawn proposed Standards. In light of these problems, repeated revisions, and defeat of the Standards, it is fair to assume that any renewed effort to promulgate standards will be facing some serious challenges.

4.26  The procedural traditions of England, Australia, and Canada are often characterized as generally less starkly adversarial than the United States. In keeping with these characterizations, these jurisdictions place more restrictions on attorneys in their interactions with witnesses generally, and with expert witnesses in particular. As noted in Chapter 2, the common practice of ‘preparing’ a witness —particularly rehearsing questions and answers—would be considered unethical in Australia and England, and illegal in Canada.⁴⁹ Despite restraints on (p. 148) advocates, many of the same concerns raised about US procedures regarding expert witnesses have also been raised in these jurisdictions.

4.27  In response to these concerns, Lord Woolf undertook to evaluate expert witness practice in England and Wales. His assessment could easily also describe concerns about the US system:

Expert witnesses used to be genuinely independent experts. Men of outstanding eminence in their field. Today they are in practice hired guns: there is a new breed of litigation hangers on, whose main expertise is to craft reports which will conceal anything that might be to the disadvantage of their clients.⁵⁰

These comments predicated the so-called ‘Woolf Report’, which in turn led to the extensive reforms in the procedural rules of England and Wales. The overall purpose of the reforms regarding expert witnesses was to compel experts to function in the service of the judge, and not simply in the interests of the party that retained the expert. To that end, the reforms included many rules that provide guidance to experts on how to fulfil this new mandate.⁵¹ Not all assessments of the Woolf reforms are uniformly laudatory. Most practising barristers report, however, that there has been a significant shift in practices and decorum involving experts in English courts since the reforms were implemented.⁵² In light of their success, the Woolf Reforms have inspired similar, and in some instances even more far-reaching, reforms in Australia,⁵³ Canada, Hong Kong, Singapore, and New South Wales.⁵⁴ Canada’s reforms are particularly interesting. Following Australia’s lead, in 2010 the Federal Court in Canada similarly introduced a Code of Conduct as a schedule to the Federal Rules of Court. The Code requires counsel to provide expert witnesses with the Code of Conduct when they are initially retained and further requires that expert witnesses sign a certificate acknowledging that they agree to be bound by the Code.⁵⁵

4.28  Another innovation introduced in Australia, and more recently in England, is expert witness ‘hot-tubbing’ (also referred to as ‘concurrent evidence’, ‘joint meeting’, ‘expert conferencing’, (p. 149) and ‘witness conferencing’).⁵⁶ The essence of hot-tubbing is that the experts present their findings to the court virtually simultaneously. After being sworn in together, the experts in turn summarize key findings and ask questions of and respond to the opposing expert. Subsequently, counsel and the court may or may not cross-examine and question the experts, who may, in turn, again have opportunities to elaborate.⁵⁷ Although criticized by some,⁵⁸ hot-tubbing has also been commended as an effective technique to save time and hone in on key areas of dispute.⁵⁹

4.29  Joint conferencing is another procedural innovation that has been used with success in Australian courts⁶⁰ and is now recognized under Australian federal rules and New South Wales.⁶¹ Similar to hot-tubbing, joint conferencing also allows discourse between two or more experts. The difference is that in joint conferencing, the experts meet outside of court and off the record. The experts then produce a document outlining areas of agreement and disagreement discussed during the joint conference.⁶² Joint conferencing is used in international arbitration,⁶³ but is also still subject to scepticism about its adequacy for exceptionally complex scientific issues that involve mixed questions of law and fact.⁶⁴

(p. 150) 4.30  As discussed in greater detail later, these reforms curbed some of the most extreme excesses in those jurisdictions that have adopted them. The function of experts, however, remains largely the same (i.e., they are selected, compensated, and prepared by parties and their counsel). It remains exceedingly rare for judges to appoint expert witnesses directly, and the procedural reforms described earlier have not completely dispelled that reluctance.⁶⁵ As a result, there remain questions about the true value of the reforms,⁶⁶ as well as more precise questions about which aspects of the reforms have effectuated the most significant changes.

4.31  In civil law systems, such as Germany and the Netherlands, conventional procedures for court-appointed experts have also been subject to criticism, and some exceptions have developed to redress concerns. The advantage of tribunal-appointed experts is that they avoid many of the biases introduced by an adversarial process in which experts are selected and paid by parties and work intimately with parties’ legal advocates in the development of case strategy. While this is an obvious advantage, more recent criticism takes aim at the extent to which court-appointed experts are, or can be considered to be, completely unbiased. The notion of objectivity or neutrality in an expert witness, it is argued, is based on an unduly restrictive definition of bias.

4.32  While the cognitive biases of expert witnesses have not been studied as extensively as those of judges (and, by extension, arbitrators) they are an unsurprising by-product of the fact that experts, like judges and arbitrators, are human.⁶⁷ Despite training and even scientific understanding of cognitive biases, experts are not themselves insulated from cognitive biases that affect all humans. Some of these biases are particularly prevalent, and uniquely troubling, in legal decision-making. One is the so-called anchoring bias, in which individuals facing a complex decision rely on initial reference values that may be incomplete or irrelevant in making their final assessment. For instance, litigators may hypothesize a low damage estimate to an expert in an initial meeting that then becomes the basis for a cognitive anchor in later ostensibly independent analysis.⁶⁸ This form of cognitive bias, and the erroneous analysis it (p. 151) can produce, is difficult to dispel, even when the expert knows that anchoring information is from a source that has low credibility.⁶⁹ While this potential for innocent or unknowing expert witness bias raises some concerns about the information parties’ and their counsel provide to expert witnesses, it and other known cognitive biases also raise fundamental questions about the possibility for any expert, including a court-appointed expert, to be truly ‘unbiased’.

4.33  While presumably free of pressure from parties, tribunal-appointed experts may be subject to various types of cognitive and heuristic biases that are introduced by their own background and training, personal beliefs, or ‘prevailing culture’.⁷⁰ As Stephen Jay Gould, famed evolutionary biologist and popular science writer, explained:

Facts are not pure and unsullied bits of information; culture… influences what we see and how we see it. Theories, moreover, are not inexorable inductions from facts. The most creative theories are often imaginative visions imposed upon facts; the source of imagination is also strongly cultural.⁷¹

Gould is expressing here the same sentiment as Marcus Aurelius at the beginning of the chapter. Objective perception of facts and assessments of truth are subject to the limitations of sensory perception and the cognitive biases that affect how humans, including experts, process information.

4.34  In the adjudication context, an expert opinion is an assertion of expert knowledge regarding an interpretation of, or prediction about, an often complex amalgam of observable facts.⁷² It is not usually, in itself, an objective fact or an individual’s recollection of an objective fact.⁷³ Applying Gould’s observation to expert witnesses, in processing data to make an expert interpretation or prediction, the expert witness necessarily refracts the data through his or her experience and predispositions. This refraction is not so much an aberration, but in fact part of why experts with particular backgrounds or forms of expertise are selected, by either parties or tribunals.

4.35  Reliance on a single, tribunal-appointed expert obscures this reality. Instead, when a tribunal appoints a ‘neutral’ court-appointed expert, the process itself implies that there is only one right answer to the complex issues that are the subject of expert testimony.⁷⁴ In (p. 152) some instances, the tribunal’s selection of an expert from one school of thought (as opposed to another) can be outcome determinative.⁷⁵ Meanwhile, reliance on tribunal-appointed experts may also discourage introduction of novel legal theories that might be sustained by expert testimony.⁷⁶

4.36  Bias in cognition of so-called neutral experts may seem less pernicious than biases that result from adversarial attempts to co-opt expert opinions. They can, however, be even more problematic precisely because they are more likely to escape detection or challenge.⁷⁷ As a practical matter, it can be exceptionally difficult for parties to challenge a court-appointed expert’s opinion, particularly since expert analysis may be needed to identify the source of certain errors.⁷⁸ Even if an important error were found by a party-retained expert, the perceived neutrality of tribunal-appointed experts may cause adjudicatory decisionmakers (judges, juries, or arbitrators) to treat their testimony as unassailable.⁷⁹ In other words, the perception of impartiality may create an undeserved ‘aura of infallibility’ for tribunal-appointed experts.⁸⁰ As one scholar notes, ‘All error is problematic, but unrebutted error is especially so.’⁸¹

4.37  In an effort to redress this problem, most procedural rules in national legal systems and in international arbitration preclude adjudicators from treating expert opinion as decisive on an issue.⁸² These rules legally require tribunals to make an independent determination of (p. 153) the issue on which expert testimony is offered. The impulse to defer, however, is strong, particularly when there is only one source of expert testimony and the issue is extraordinarily complex. The most ardent critics argue that the impulse to defer is more operative than expected or desirable.⁸³

4.38  Another potential protection against these concerns about court-appointed experts is that civil law systems increasingly permit parties to retain their own experts.⁸⁴ As a practical matter, however, parties rarely do. There are several reasons for this reluctance. First, experts can usually be appointed by a party only if the court grants the party permission. When such experts are permitted, their opinion does not generally have the same value as that of a court expert.⁸⁵ Instead, in civil law systems, an opinion by a party-selected expert is generally treated as an assertion of a party, not as evidence.⁸⁶ As a consequence, the party submits the expert’s report to the court, but the party-selected expert is not examined at trial.⁸⁷ The utility of party-selected experts is thus generally limited in civil law systems, making it difficult to justify any benefit as weighed against the cost of retaining an outside expert. Just as courts are reluctant in the United States to appoint experts to counterbalance excessive partisanship of party-selected experts, parties in civil law systems are sceptical about the value of party-selected experts to counterbalance concerns about court-appointed experts.

4.39  To understand the ethics of expert witnesses in international arbitration it is also useful to look at existing practices in public international courts. Like international arbitration, these tribunals also adjudicate disputes among parties from various cultural and legal traditions, and consequently share many of the same challenges faced by international arbitral (p. 154) tribunals.⁸⁸ A major difference is that public international tribunals are tethered to State- and treaty-based rules and may be less flexible than international arbitral tribunals that are the product of private party agreement.⁸⁹ Nonetheless, with increasing reliance on expert witnesses to opine on scientific and technical matters, public international courts have etched a growing record of procedural innovation in assimilating expert evidence.

4.40  Both public international tribunals⁹⁰ and parties in proceedings before those tribunals are generally presumed to have powers to appoint experts. In contrast to national jurisdictions, public international adjudications often use a combination of both party-selected and tribunal-appointed experts simultaneously, and like recent reforms, have them operate in dialogue with each other.⁹¹ Another procedural innovation for seeking expertise, which arguably avoids at least some of the concerns with existing national practices, is for tribunals to seek out independent outside international organizations for expert advice. For example, the International Court of Justice (ICJ) rules specifically provide for opinion requests from public international organizations such as the World Health Organization (WHO).⁹² World Trade Organization (WTO) panels have similarly sought expert advice for international organizations.⁹³ The use of such organizations in place of experts can raise unique concerns (p. 155) about independence since, like individual experts, organizations often have their own policy objectives that can affect their assessment of particular issues.⁹⁴

4.41  Another, less salutary development is that some international courts have diluted or dissolved altogether the delineation between advocates, arbitrators, and experts. In the ICJ context, expert witnesses have appeared in court in the role of full advocates or counsel.⁹⁵ In the Gabcıkovo-Nagymaros case,⁹⁶ for example, Hungary had its four scientists appear as ‘advocates’ while Slovakia had its two scientists appear as ‘counsel and experts’. Counsel for Hungary made a point of clarifying that Slovakia’s scientists, like Hungary’s scientists, appeared as advocates.⁹⁷ Similarly, in the Case concerning Pulp Mills,⁹⁸ both parties included six delegation members as ‘scientific advisors and experts’. Correspondence between the parties clarified that these representatives were speaking in the capacity of advocates rather than expert witnesses.⁹⁹ The perceived advantage of experts-as-advocates is that it arguably eliminates concerns about expert biases and shifts the enquiry from questionable assumptions about independence to more direct questions about persuasiveness on the substance of the issue. Such blurring of roles, however, requires considerable procedural jerry-rigging concerning how to handle examination and cross-examination of experts, whether or not to require standard expert oaths,¹⁰⁰ confusion of mixed issues of fact and law, and misconstruction of professional ethical obligations.¹⁰¹ In fact, experts-as-advocates created such difficulty in Pulp Mills that in a separate opinion one judge specifically criticized the practice and underlined the Court’s ‘unequivocal indication’ that ‘the practice should not be repeated in future cases’.¹⁰²

4.42  Another practice that occurs among public international tribunals is the allowance of direct appointment of experts to the tribunal,¹⁰³ either by appointing experts directly as voting or non-voting members of the panel, or conscripting technical assessors to advise the panel.¹⁰⁴ For example, both the ICJ and tribunals formed under the UN Convention on the Law of the Sea (UNCLOS) retain power to appoint non-voting experts to the tribunal.¹⁰⁵ The perceived (p. 156) advantage of this approach is to ensure the panel’s ability to identify, understand, and address technical issues in a more efficient manner than formal admission of expert evidence.¹⁰⁶ This blurring of roles, this time with experts-as-adjudicators, raises similar and even more significant concerns, however, about these experts’ potentially excessive (and non-transparent) influence on the tribunal.¹⁰⁷ Expert input directly to the tribunal bypasses evidentiary processes and precludes any opportunity for parties to comment, challenge, or refute.¹⁰⁸ Perhaps due to these concerns, arbitrators appointed based solely on scientific or technical qualifications are relatively rare, and primarily used under narrow jurisdictional guidelines for highly technical matters.

4.43  Where experts are required on a tribunal, courts generally maintain a permanent roster of technical experts in order to facilitate selection by the parties.¹⁰⁹ For instance, experts chosen for special arbitral tribunals under Annex VIII of UNCLOS are selected from lists of experts in a range of environmental and maritime fields; individuals on those lists are nominated by Member States and the lists themselves are maintained by subsidiary bodies or public international organizations.¹¹⁰ Drawing experts from permanent, formally maintained lists is a practice that is also used in certain civil law jurisdictions.¹¹¹ Commentators have urged expanding the practice in the international public law context—notwithstanding the potential impracticalities of maintaining up-to-date lists of experts in a wide range of fields and subject matters.¹¹²

4.44  Another expert procedure worth adding to this survey is the unique WTO two-phase procedure for assimilating expert evidence.¹¹³ In the first phase, the tribunal submits a list of written questions to the experts based on party requests submitted to the tribunal. After the experts provide written responses, parties may comment on both the expert responses and the comments of other parties, which are then circulated to all parties and experts. The tribunal then drafts a report on the preliminary questions, seeking confirmation of the report’s accuracy from the experts where necessary. The second phase consists of ‘joint meetings’, whereby the parties, experts, and arbitrators meet together to clarify the issues. First, the experts introduce and discuss the issues and party comments. The parties submit follow-up questions, which are relayed by the tribunal to the experts, who provide on-the-spot answers. (p. 157) The arbitrators may then ask for clarification of certain points, after which the experts provide closing statements. Finally, experts may comment on the transcript of the joint meetings before it is entered into the record.

4.45  Joint meetings share much in common with hot-tubbing, outlined in Section A.2.b. The major difference with the WTO practice is that the tribunal acts as an intermediary between experts and parties, which eliminates cross-examination and separate pleading. Proponents of the WTO approach argue that it promotes clarity on technical issues and enough flexibility to accommodate all parties.¹¹⁴ Critics, meanwhile, complain that it has an off-the-cuff nature that reduces predictability, and that time constraints on oral meetings may lead to incomplete answers and back-of-the-envelope data guesstimates instead of needed precision.¹¹⁵

4.46  Many of the innovations that exist in international tribunals are either not feasible or perhaps not particularly desirable in international arbitration. They demonstrate, however, that the role of expert witnesses is not limited to the formulations developed in national legal systems. With this background of expert witnesses in national legal systems and before public international tribunals, the next part turns to the ethics of experts in international arbitration.

4.47  The inability of the national procedural reforms to resolve perceived problems in national legal systems is, at least in part, symptomatic of legal transplants more generally. A ‘legal transplant’ is a ‘doctrine or legal rule that is transposed from one legal system into another’.¹¹⁶ The reforms described in earlier sections seek to permit court-appointed experts in common law systems and party-selected experts in civil law systems. Unfortunately, these ‘legal transplants’, like their botanical counterparts, are not always adaptable to a new climate. There is extensive scholarly analysis of the reasons why some legal transplants ‘take root’ and others are rejected as incompatible with the host state’s ‘procedural ecology’.¹¹⁷ In the case of expert (p. 158) witnesses, the procedural innovations did not mesh well with culturally entrenched,¹¹⁸ longstanding, and familiar processes.¹¹⁹ Instead, they ‘pushe[d] against the deeply ingrained norms, roles, and incentive structures’ in the respective systems.¹²⁰

4.48  In contrast to largely unsuccessful legal transplants at the national level, international arbitration provides exceptionally fertile ground for procedural innovations.¹²¹ The ‘norms, roles, and incentive structures’ that inhibit reform at a national level are not firmly entrenched in international arbitration procedures. Quite the opposite; international arbitral procedures were developed to accommodate parties, arbitrators, and counsel from different legal cultures. The prevailing procedures in international arbitration are those that have proven popular and effective to parties, counsel, and arbitrators from many jurisdictions working together. As a result, they usually represent procedural hybridizations based on an amalgam of national procedural traditions that have had their mettle tested in international arbitral proceedings.¹²²

4.49  The prevailing international arbitral procedures have been distilled down and codified in the International Bar Association (IBA) Evidence Rules.¹²³ While this codification provides (p. 159) a degree of continuity and shared understanding, unlike national rules, the IBA Evidence Rules are not founded on as culturally entrenched norms as are rules in national legal systems. Efforts to reform the IBA Evidence Rules are subject to the same political wrangling that occurs with any negotiated compromise in cross-cultural settings. There are, however, much lower hurdles at the international level than the potentially insurmountable political obstacles that must be overcome to ratify reforms within national legal systems.

4.50  In international arbitration, reforms are adopted at the retail level. Proposed reforms are not imposed as top-down pronouncements, but as flexible options that are distilled out of prevailing practices and can be adopted in particular cases. Unpopular reforms are simply ignored or rejected. As discussed later in this chapter, this measure of freedom affords international arbitration an opportunity to redefine the role, and correspondingly define the ethical obligations, of the expert witness in a manner that is simply not as feasible in national legal systems.

4.51  Since States do not generally regulate the ethics of experts appearing in their own national court proceedings, it is not surprising that national arbitration laws generally ignore the ethics of experts in arbitral proceedings. Both institutional and ad hoc international arbitral rules are similarly elliptical about the conduct and ethical obligations of expert witnesses.¹²⁴ Recently, the topic of expert ethics has garnered interest from commentators,¹²⁵ but the direction of future reforms is not yet certain. The establishment of ethical standards for experts raises some unique challenges and opportunities for international arbitration.

4.52  One additional challenge in regulating expert witnesses in international arbitration is that, unlike domestic legal systems, there is no single predominant model for how expert witnesses are appointed and function. International arbitration permits a range of possible models for expert witnesses. While this flexibility creates some challenges, it also affords unique opportunities for new regulation at the international level and within international arbitral procedures. To the extent that the most promising reforms seek to re-acculturate participants and restructure the role of experts, such reforms may be more feasible in international arbitration than they are in domestic systems, where the role of experts is more culturally entrenched.(p. 160)

4.53  In the remainder of this chapter, Subsection 1 explores procedural innovations, often inspired by some of the national reforms described in the previous part. The prevailing standards and practices in international arbitration focus on efforts to improve them. Subsection 2 considers a few deviations from standard practice that cause problems, and finally Section C assesses certain reforms that have recently been introduced in international arbitration.

4.54  One hallmark of international arbitration’s procedural flexibility is that it aims to accommodate party preferences. As a result, the nature of and procedures for introducing expert witness evidence often depend on party preferences. These preferences are usually determined by express agreement or indirectly as determined by the predilections of arbitral tribunals selected by the parties. Tribunals comprised of arbitrators from common law jurisdictions will ordinarily permit the parties to present party-selected expert witnesses through procedures consistent with the traditions in common law systems.¹²⁶ In contrast, parties or tribunals dominated by specialists from civil law backgrounds ‘may be more skeptical about the benefits and costs of party-nominated expert witnesses’.¹²⁷ It still happens that civil law dominated arbitral tribunals, ‘particularly more traditionally-minded ones’,¹²⁸ may permit only tribunal-appointed experts.

4.55  New rules are increasing flexibility and making expert witness options more expressly subject to individual party preference, even absent mutual party agreement. For example, the IBA Evidence Rules provide that ‘A Party may rely on a Party-Appointed Expert as a means of evidence on specific issues’¹²⁹ and that in response to a Report from a tribunal-appointed expert, ‘any party shall have the opportunity to respond to the Expert Report’ by various means including through ‘an Expert Report by a Party-Appointed Expert’.¹³⁰ These provisions seem to create rights for parties to use party-selected experts that are not conditioned either on tribunal permission or agreement from an opposing party.

4.56  More generally, the IBA Evidence Rules provide a number of innovative options including preliminary party-selected expert conferences, rights to cross-examine, access materials relied upon by tribunal-appointed experts, and even hot-tubbing.¹³¹ These rules can be mixed and matched in whole or in part.¹³² While historically arbitral rules were more predisposed towards either common law or civil law approaches,¹³³ institutions are increasingly hybridizing and addressing in more detail the manner expert evidence is assimilated. For example, (p. 161) the Chartered Institute of Arbitrators (CIArb) provides online practice guidelines covering procedures and strategies for using party-selected and tribunal-appointed experts.¹³⁴ The China International Economic and Trade Arbitration Commission (CIETAC) also recently expanded its arbitration rules to allow for oral expert evidence,¹³⁵ and the International Chamber of Commerce (ICC) includes a special International Chamber for Expertise that can be consulted to recommend or appoint experts or even administer expert proceedings under its rules.¹³⁶

4.57  In addition to procedures that have been distilled into formal rules and protocols, other innovations are also being experimented with on an ad hoc basis. For example, ‘expert teaming’ (also known as ‘Sachs protocol’) is regarded as an innovation that finds middle ground between party-selected and tribunal-appointed expert traditions.¹³⁷ In expert teaming, the tribunal first invites parties to each provide a short list of potential expert candidates. Then, the tribunal chooses one expert from each list jointly as an ‘expert team’.¹³⁸ Afterward, parties and the tribunal may choose other procedures for presenting expert evidence and examining the experts, such as cross-examination, expert conferencing, and the like.

4.58  In the alternative, parties and tribunals may craft something similar to the two-phase procedure used in the WTO (discussed earlier). In fact, this system that has arisen as ‘the de facto standard procedure in the WTO’ itself sprouted organically from nebulous procedural guidelines and the unique conditions of WTO proceedings.¹³⁹ Witness conferencing is already apparently on the rise.¹⁴⁰ Other expert witness procedures may also evolve in international arbitration given its similarly flexible procedures and continued efforts to find efficiencies.

4.59  Like rising consciousness about the costs associated with ambiguity about counsel ethics, there is an increased recognition that the absence of regulation regarding expert ethics may increase the costs and reduce the accuracy and efficiency of arbitral proceedings. As a result, calls for and efforts at reform have increased.

4.60  Although ostensibly evidentiary rules, not ethical rules, the IBA Evidence Rules have attempted to take on this challenge. The drafters of the IBA Evidence Rules expended significant effort on expert witnesses, dedicating separate articles to party-appointed experts (Article 5) and tribunal-appointed experts (Article 6). These new articles contribute some measured progress in delineating the distinction between party-selected and tribunal-appointed experts. Ultimately, however, the Rules may do more to highlight problems than to resolve them. They also make assumptions and impose obligations that will likely have to be reconsidered in subsequent revisions to the Rules.¹⁴¹

4.61  The first point of concern involves the unequal, and arguably inverted, disclosure obligations imposed on different types of experts. Under Article 5 of the IBA Rules of Evidence, party-selected experts are specifically required to state their ‘present and past relationship (if any) with any of the Parties, their legal advisors and the Arbitral Tribunal’.¹⁴² Curiously, there is no similar disclosure obligation imposed on tribunal-appointed experts. This omission is surprising because the Rules confer on tribunal-appointed experts powers that are analogous to, and even commensurate with, those of the tribunal. For example, the tribunal-appointed expert has the power to request and access information, and the expert’s authority to do so is described as ‘the same as the authority of the Arbitral Tribunal’.¹⁴³ How can an expert have powers similar to the tribunal but not be subject to disclosure qualifications to ensure that those powers are exercised in a fair and equitable manner?

4.62  While disclosure obligations are limited to party-selected experts, both party-selected and tribunal-appointed experts are required to submit a statement of their ‘independence from the Parties, their legal advisors and the Arbitral Tribunal’.¹⁴⁴ This statement of independence seems reasonable as a requirement for tribunal-appointed experts, but further emphasizes the oddity of not requiring separate disclosure. A tribunal-appointed expert may have some ‘present or past relationship’ that would be disclosable under the standard announced in Article 5.2(a) for party-selected experts, and presumably should be disclosed. That same information may not be sufficient to preclude a tribunal-appointed expert from acting independently and therefore may not be deemed sufficient to interfere with submission of the (p. 163) requisite statement of independence.¹⁴⁵ For example, what if a tribunal-appointed expert were testifying in other cases before members of the same arbitral tribunal on similar issues? Or if the tribunal-appointed expert had been appointed several times in the past year by one of the parties’ law firms? Why should such information be required to be disclosed by a party-selected expert, but not a tribunal-appointed expert? To the extent that party-selected experts’ disclosure obligations are important to reveal a suspected intellectual tilt, why is the same information deemed irrelevant for those experts who are presumed to have no tilt?

4.63  This incongruence is especially peculiar given that disclosure of information by a party-selected expert is arguably less critical. For party-selected experts, other protections exist to test their credibility, such as cross-examination and the substantive testimony of an opposing party-selected expert.

4.64  Apart from the IBA Evidence Rules, disclosure of conflicts of interest is a potential reform that has been suggested to clarify expert witness’ independence and potential influences.¹⁴⁶ Experts should be and generally are required to disclose their level of compensation and the number of repeat engagements for a particular party, law firm, or professional perspective. Some industry regulations also require disclosure of conflicts of interest. Consistent with the general focus of industry-based regulations, those requirements are usually aimed at the conduct of experts in their primary professional occupation, not when they are ‘moonlighting’ as expert witnesses.¹⁴⁷ Moreover, overly rigorous expert disclosure of potential conflicts of interest may not be a cure-all and can potentially be counterproductive. In one study, experts required to disclose conflicts of interest were less accurate in their expert advice, ‘perhaps because the disclosure made experts feel some sense of “moral license”’.¹⁴⁸ Even if not a panacea, disclosure of potential conflicts is an important means of increasing transparency, which may in turn press parties to be more careful in selecting experts who are free from obvious and discrediting conflicts.

4.65  The IBA Evidence Rules also impose what purports to be a uniform duty of ‘independence’ on both party-selected and tribunal-appointed experts.¹⁴⁹ In this respect, the IBA Evidence Rules are not unique. For example, the Protocol for the Use of Party-Appointed Expert Witnesses in International Arbitration developed by the Chartered Institute of Arbitrators provides that: ‘An expert’s opinion shall be impartial, objective, unbiased and uninfluenced by the pressures of the dispute resolution process or by any party.’¹⁵⁰ Similarly, the IBA Rules purport to apply the same obligation of ‘independence’ to both party-selected and tribunal-appointed experts.

(p. 164) 4.66  The phrase ‘independent party-selected arbitrator’ sounds more like an oxymoron than a reasonable aspiration. Almost definitionally, a party-selected expert is not ‘independent’ of the selecting party, at least not in the same way that a tribunal-appointed expert is expected to be ‘independent’. Party-selected experts are compensated by the one party. They receive instructions from and engage in extended communications with the counsel for that party. They testify or submit reports ‘on behalf of’ or ‘in support of’ that party’s case and they are cross-examined only by the opposing party. In light of these factors, a party-selected expert cannot be considered ‘independent’ in the same sense that the term is generally used with respect to tribunal-appointed experts, or other professionals to whom the same term is applied.

4.67  Even if the IBA Evidence Rules ascribe an inconsistent and muddled meaning to the term ‘independent’, in some respects, the drafters were only replicating a problem that already exists in other contexts. First, there is an apparent analogy between party-appointed arbitrators and party-selected experts. Under most arbitral rules, all members of an arbitral tribunal, including party-appointed arbitrators, must sign a statement or otherwise attest to their independence from the parties.¹⁵¹ Many sources that regulate arbitrator conduct also underscore that party-appointed arbitrators are bound by the same ethical standards—including a duty of independence—as arbitral chairpersons. As examined in greater detail later in Chapter 8, however, key differences exist between party-appointed arbitrators and chairpersons that directly affect the nature of their independence obligations.

4.68  Even if there are interesting comparisons between party-selected experts and party-appointed arbitrators, there are also important differences. A party-appointed arbitrator’s obligation of independence generally precludes compensation by only one party (though some rules, such as the American Arbitration Association (AAA) and International Centre for Dispute Resolution (ICDR), permit the practice). Meeting ex parte with only one party is generally regarded as incompatible with an arbitrator’s obligation of independence. Under the historic US practice of highly partisan party-appointed arbitrators,¹⁵² some courts reasoned that ex parte communications, non-disclosure of conflicts, and even unilateral compensation were permissible for party-appointed arbitrators.¹⁵³ In those circumstances, courts reasoned that such conduct was permissible because those highly partisan party-appointed arbitrators were not expected to be independent of the parties.¹⁵⁴ As described in Chapter 8, this US practice is (p. 165) now largely discredited and mostly abandoned. US party-appointed arbitrators now generally abide by rules that forbid such on-going ex parte communications and instead require independence.¹⁵⁵ The reasoning of these earlier decisions, however, is helpful to understanding why party-selected experts are not ‘independent’. For party-appointed arbitrators, abstaining from ex parte communication is one of the hallmark distinctions between those who are independent and those who are not. Since party-selected experts are selected and compensated by only one party and expected to coordinate and communicate with appointing parties and their counsel, they could not meet this hallmark of ‘independence’, at least not in the same sense that that word is used to describe party-appointed arbitrators.

4.69  To avoid this illogical application, it could be argued that Article 5’s statement of independence for party-selected experts should be interpreted as an expression of the expectation that all experts, regardless of how appointed, will bring to the issues of their expertise ‘independent professional judgment’.¹⁵⁶ While the independence or ‘objectivity’ of expert opinions will be discussed in greater detail later in the chapter, the text of Article 5 does not readily lend itself to this interpretation. Article 5 does not use ‘independent’ as a modifier for the party-selected expert’s judgment, testimony, or opinion. Instead, it refers to party-selected experts’ status in relation to the parties who appoint them. In this regard, the term ‘independent’ is used exactly as it is with respect to tribunal-appointed experts in Article 6 of the IBA Evidence Rules, and in the same manner as it is generally applied to members of the arbitral tribunal.¹⁵⁷ While it might be hoped, expected, and generally desirable to encourage party-selected experts to exercise independent professional judgment, simply requiring them to state (inaccurately and disingenuously) that they are ‘independent’ of the parties, counsel, and the tribunal does not accomplish that aim. It may even undermine that goal by forcing an illogical recitation that is contrary to their actual status and practice.

4.70  The general statement of independence, as imposed by the new IBA Evidence Rules, may not be a meaningful solution as applied to party-selected experts. There are, however, some procedural innovations that aim at a similar outcome and may have a better chance of ensuring more reliable expert witness testimony.

4.71  In light of recent reforms in national systems such as England, Canada, and Turkey¹⁵⁸ that require experts to swear oaths, some international arbitration commentators have argued that this obligation could be a useful innovation to adopt in international arbitration.¹⁵⁹ (p. 166) Despite the apparent appeal, oath-swearing alone (at least as is typically done just prior to testimony) is not likely to provide a meaningful solution. As a threshold matter, some national laws do not permit arbitrators to administer oaths in arbitral proceedings that are seated in those jurisdictions.¹⁶⁰ As a result, oath-swearing could not be a universally available reform. At a more fundamental level, expert witness oaths would have certain limitations as compared to fact witness oaths, which may make them less effective.

4.72  Some national judicial systems require experts to take an oath, similar to fact witnesses, to tell ‘the truth’. Since an expert witness’s most critical testimony is often in the form of opinion, however, the basic true-false dichotomy addressed by fact witness oaths are not easily applied, either as a conceptual or a practical matter. An opinion can be unreasonable, unfounded, unsupportable, and unconventional.¹⁶¹ An opinion cannot, however, be ‘false’, at least not in the same way that a statement of fact can be false.¹⁶² As discussed in greater detail later,¹⁶³ it is much more difficult to regulate the unreasonable, unfounded, unsupportable, or unconventional than it is to regulate simple falsehoods.

4.73  Generally, the deterrent effect of an oath lies primarily in the threat of prosecution for perjury. As a legal matter, however, many national laws are relatively tolerant when it comes to potential punishment for witness perjury, particularly in international arbitration.¹⁶⁴ Many systems simply do not extend their perjury laws to witnesses in international arbitration.¹⁶⁵ Even in those jurisdictions whose law technically extends to witnesses in international arbitrations, national prosecutors have little interest in chasing down errant witnesses who made alleged misstatements in exotic proceedings that are detached from their national legal system. The general reluctance of national prosecutors to pursue criminal investigations for conduct in international arbitrations is probably best demonstrated by the unwillingness of Swiss prosecutors to investigate rather sensational allegations of fraud and misrepresentation in a very highly publicized case in which counsel and parties apparently falsely accused (p. 167) esteemed members of an arbitral tribunal of accepting bribes.¹⁶⁶ Prosecutions based on conduct in international arbitrations, however sensational, are exceedingly rare and improbable, even for factual witnesses.¹⁶⁷

4.74  Prosecution for allegedly perjurious testimony by an expert witness presents an even greater challenge, even if national prosecutors could be prompted to intervene. First, as already noted, expert witnesses present their most salient testimony as ‘opinion’, not ‘fact’. Second, expert opinions are usually based on complex analysis of a specialized field of study. Indeed, the entire reason to procure an expert is to assist the decisionmaker in resolving a question that is so complex as to require specialized training and experience. Both of these factors make it exceedingly difficult to prosecute expert witnesses for allegedly perjurious testimony.

4.75  Since, epistemologically, expert knowledge is not simply true or false in the same way that factual knowledge is, its accuracy must be broken down into three component parts: belief, truth, and justification.¹⁶⁸ As one scholar explains:

Belief is a person’s subjective position concerning the truth of a proposition. Truth is the reality of the proposition independent of belief. Justification involves the quality of the reasons for a belief. To count as knowledge, something must be believed as true, it must be true, and a person’s belief that it is true must be justified. In the absence of a belief, what we have is ignorance. In the absence of truth, what we have is error. In the absence of appropriate justification, what we have is mere opinion.¹⁶⁹

In other words, a fact witness testifies regarding the truth of a factual proposition. By contrast, an expert witness testifies regarding his or her belief regarding the truth of an underlying proposition.

4.76  Given the nature of expert witness testimony, it is treated as legitimate, meaning it can be treated as scientific knowledge, if it is justified. A court or arbitral tribunal ultimately must decide for itself the truth of the underlying proposition and, as already noted, many national laws prohibit tribunals from substituting expert opinion for their own legal decisions. An expert is not testifying regarding the truth or falsity of the underlying proposition, but instead only regarding the expert’s belief which is presumably justified by the expert’s knowledge of the field and careful study of the problem. In other words, an expert testifies as to a belief and gives reasons why that belief is justified. The adjudicator must ultimately decide the truth of the proposition.

4.77  Even if the two essential elements of expert testimony—sincere belief and effective justification—are lacking, prosecution for perjury would still be exceedingly difficult.¹⁷⁰ On the one hand, an (p. 168) expert can have a belief that is sincere, but false. For example, not only did ‘scientific experts’ in Galileo’s era (today, we would call them ‘church officials’ or ‘religious scholars’) sincerely but inaccurately believe that the sun travelled around the earth, but also that the geocentric theory of celestial bodies was an inalienable epistemological ‘fact’. At Galileo’s trial, if an expert had testified to that sincerely held belief, the expert could not be prosecuted under modern perjury statutes, even though they were completely wrong about the underlying proposition.¹⁷¹

4.78  In modern times, the main critique of expert witnesses is that the beliefs they espouse are insincere, not sincere but mistaken. It would, however, be equally unlikely to have an insincere belief satisfy the modern elements for criminal perjury. Apart from the problems of proving a mental state like insincerity, the modern elements of criminal perjury usually require the defendant 1) be under oath during testimony, 2) make a false statement, 3) make a false statement with knowledge of its falsity, and 4) the false statement must be material to the proceedings.¹⁷² Falsity and knowledge of falsity are not standards that fit easily with the nature of expert opinion testimony.

4.79  Another prevailing modern critique of expert witnesses is that even if they sincerely believe in an underlying proposition (or that belief is not easily challenged), that apparent belief is not justified. Such testimony might be reckless and illegitimate. It would be difficult, however, to characterize even reckless testimony as ‘perjurious’, at least in the modern sense of the term. For example, a gambler may have a vehement belief that his lucky number is going to come up on the next spin of the roulette wheel. The gambler may end up being right (and win a lot of money). That outcome, however, would not be the product of ‘knowledge’, despite the gambler’s sincere belief that he ‘just knew’ his number was going to come up.¹⁷³

4.80  The reason this analogy may seem implausible in comparison to expert testimony is because, even to a layperson, the mechanism of the roulette wheel and the odds of a selected number (p. 169) coming up are both well known. These well-known facts make the probability of the lucky number actually coming up easily verifiable. As a result, the absence of justification seems obvious. With most expert testimony, the absence of justification is more difficult to discern because the underlying proposition is less certain and the methodology used by experts is more opaque to laypersons than the mechanics of a roulette wheel. These circumstances make the absence of justification a difficult predicate for a perjury charge.

4.81  While perjury charges against expert witnesses are almost unheard of, admissibility standards can preclude the introduction of frivolous expert testimony. In most United States jurisdictions, scientific expert testimony is admissible only if it satisfies the so-called Daubert standard, which requires a judge to act as a gatekeeper in determining whether expert testimony proceeds from ‘scientific knowledge’ and is based on sound scientific methodology before they deem it admissible.¹⁷⁴ Admissibility standards can play a meaningful role by excluding from evidence expert testimony that is not founded on sound methodology—in other words not justified. These standards generally only exclude questionable categories of expert testimony, however, and do not screen out flimsy opinions issued within a legitimate category of scientific evidence.

4.82  The Functional Thesis, developed in greater detail in Chapter 7, posits that the procedures in any adjudicatory setting portend the functional inter-relational roles of particular actors, such as expert witnesses. These inter-relational functional roles, in turn, establish a particular range of ethical obligations and limitations that further fulfilment of specific actors’ (in this case, expert witnesses’) role and help identify the factors to be taken into account in making ethical decisions. The Functional Thesis holds two important insights for expert ethics.

4.83  On the one hand, tribunal-appointed and party-selected experts have different inter-relational roles with respect to tribunals, parties, and counsel. The functional role of the tribunal-appointed expert is to assist the tribunal directly and, in this role, to prepare an expert opinion in a manner that is financially and operationally separate from the parties, and may even include tribunal-like powers over the parties. For this reason, the ‘independence’ required of a tribunal-appointed expert precludes the expert from accepting money from only one party or meeting privately with counsel for one party.

4.84  The functional role of the party-selected expert, by contrast, is to develop expert evidence based on information provided by one party and in coordination with party’s counsel. This role also explicitly contemplates that the expert will accept money from and engage in communications with the counsel of only one party, and only be cross-examined by the other party’s counsel. These activities are part of the functional role contemplated for a party-selected expert. Varied roles necessarily mean varied ethical obligations. The role of a party-selected expert is not consistent with the obligation of ‘independence’ that is imposed on the very different role of tribunal-appointed expert witnesses.

4.85  International arbitration employs both types of experts, but separated from the national legal traditions in which they normally operate. This mix-and-match approach means that expert (p. 170) witnesses’ functional roles are not necessarily familiar to all participants. The earlier discussion of the IBA Evidence Rules demonstrated that international arbitration has not clearly delineated the distinct ethical obligations that apply to party-selected experts in contrast to tribunal-appointed experts. These distinctions are all the more important when parties, counsel, and arbitrators do not have shared intuitions and assumptions about what constitutes proper conduct.

4.86  In addition to mixing-and-matching the two archetypes of expert witnesses, international arbitration has also been at the forefront of procedural innovations with respect to expert witnesses, which can further confuse their roles. As described in paras 4.39–4.41, international tribunals also permit development of hybridized inter-relational roles for expert witnesses. As noted, the ICJ has allowed expert witnesses to combine their function with either advocates or tribunal members. Confusion about the nature of these hybridized roles has, in turn, led to confusion about their ethical obligations. Similarly, witness hot-tubbing and witness conferencing can allow tribunals and parties to streamline the otherwise drawn out process of sequential and often contradictory expert testimony. In creating certain efficiencies, these procedures also shapeshift the inter-relational functional roles of expert witnesses by forcing them to interact directly. This new functional role, in turn, potentially raises new issues about their ethical obligations in participating in these processes.

4.87  Donald Elliott has analogized procedural innovations to the panda’s thumb, an evolutionary development that allows an otherwise clumsy paw to efficiently strip shoots off bamboo.¹⁷⁵ Similarly, Elliott argues, procedural innovations are often creative evolutionary adaptations that allow new functions that are needed but unaccommodated by a system’s traditional structure.¹⁷⁶ Functional roles are sensitive to evolutionary pressures because they are inherently utilitarian. They are driven by pragmatism and often occur on an ad hoc basis. Ethical assumptions and expectations, however, are more constant over time. New roles may portend new ethical obligations, but those new obligations may not be readily accepted as legitimate. Even as the original role to which those obligations were tethered has slipped from its moorings, actors whose role has shifted and those who interact with them in arbitral proceedings may retain background assumptions about what constitutes proper professional conduct.

4.88  This observation about the potential separateness in evolution of inter-relational roles and attendant ethical obligations accounts for some of the confusion that has occurred in particular cases, described later. The resulting confusion cannot be cured with new labels, such as ‘independent’, or quick fixes. They require integrated reassessment of ethical obligations in light of clearly defined inter-relational roles, a topic explored later in Section 1. Even with clear role definition, expert witnesses present unique challenges for effective ethical regulation. As examined in greater detail in Section 2, some of the most effective means of regulating their integrity and professionalism may not be ethical rules at all, but instead checks that structurally corral potential excesses.

4.89  Two archetypes for expert witnesses, tribunal-appointed experts and party-selected experts, derive from national legal traditions. Under the Functional Thesis, each archetype can permit a range of legitimate conduct that is tied to the differing legal cultures and the inter-relational roles they impose among parties, counsel, and experts. Within the permissible range of conduct, expert witnesses also inevitably bring their own personal predilections. For example, some party-selected experts might be more accustomed to frequent communications with counsel during the process of writing an opinion, while others may have a personal preference or established practice of more limited communications. Despite room for flexibility within the two archetypes, problems can arise if an expert witness accustomed to operating under one archetypal role is suddenly recast in another. Alternatively problems can arise if their underlying role becomes blurred, particularly as between the two archetypes. In this latter situation, existing ambiguities about the permissible range of conduct for experts becomes even more difficult to discern.

4.90  Existing uncertainties about appropriate ethical obligations for party-selected experts reflect, and even contribute to, confusion about the role of party-selected experts in certain contexts. For example, in the CME-Czech Republic case, allegations were raised that a party-retained expert on Swedish arbitration law crossed an ethical line by acting as de facto co-counsel, actively participating in arguments, instead of as a detached expert.¹⁷⁷ Experts on law present unique questions about the role of expert witnesses. National court proceedings rarely permit ‘experts’ on law.¹⁷⁸ Instead, judges are generally presumed to be competent in their own legal system and are charged with discerning the law.¹⁷⁹ Perhaps as a consequence, there are no well-developed traditions about where to draw the line between advocacy and opining on legal advice. Whatever the line, critics of the expert’s conduct in the CME-Czech case clearly believe participation in oral arguments is outside the appropriate boundaries even if there is no clear guidance on this issue.

4.91  In other examples, the basic role of the expert witness, as either party-appointed or tribunal-appointed, has been scrambled. The result of this scrambling of roles is that the uncertain range of permissible conduct becomes even more uncertain. For example, in the International Centre for Settlement of Investment Disputes (ICSID) award SOABI v Senegal, consistent with German procedures, the tribunal appointed its own expert. It also, however, imported several aspects of US procedures, including some that pertained to the expert witness’s conduct and preparation. For example, the expert was allowed to consider information provided directly by one party, SOABI, without an opportunity for Senegal to challenge its accuracy. On several occasions, the expert was even allowed to meet ‘with SOABI and in the absence (p. 172) of representatives of the Republic of Senegal’.¹⁸⁰ Senegal objected to these meetings, but the tribunal rejected these objections, reasoning that Senegal ‘had every opportunity to challenge such information as well as the Report’s conclusions… after receiving its copy from the Tribunal’.¹⁸¹

4.92  Based on the record, it appears that the tribunal permitted the tribunal-appointed expert to engage in extensive ex parte communications with SOABI. While these meetings would be perfectly normal if the expert were appointed by SOABI, it is highly unusual given that the expert was appointed by the tribunal. The problem is not that the expert’s role was converted to be more akin to that of a party-selected expert; the problem is that the conversion was only partial. The expert apparently retained the status of tribunal-appointed expert (the expert’s report was apparently submitted to the tribunal and only then provided to opposing counsel), but operated functionally more like a party-selected expert. The expert was thus permitted to engage in conduct that might raise questions about his independence or neutrality as a tribunal-appointed expert, but not subject to the procedures that would otherwise apply if he were a party-selected expert. For example, Senegal apparently did not have any opportunity to cross-examine the expert based on the report or to retain an opposing expert to challenge his conclusions. The only remedy proposed for Senegal was that it could somehow challenge the final conclusions of the expert. Such an opportunity is of limited value, however, without any opportunity to determine what information SOABI had provided during the ex parte meetings or to retain its own expert.

4.93  The problems in these cases demonstrate that the vague ethical guidance that exists for experts is designed around the established party-appointed/tribunal-appointed dichotomy. When these distinct roles are fused or combined, the already-vague standards become more difficult, if not impossible, to apply. These problems are especially acute when the role redefinition is partial, ad hoc, or not clearly articulated in advance.

4.94  Instead of parsing the unique duties that might be tied to distinct roles assigned to expert witnesses, most efforts to address expert ethics have ignored important differences. For example, to avoid potential concerns about differences between party-appointed and court-appointed experts, some commentators have suggested that all experts simply be required to be ‘neutral’ and ‘independent’ and ‘unbiased’.¹⁸² This one-size-fits-all approach is effectively what the IBA Evidence Rules, analysed earlier, attempt to do. Just as with arbitrators,¹⁸³ however, generically applying terms like ‘independence’ for all expert witnesses cannot substitute for the hard work needed to delineate their specific inter-relational roles and consequent ethical responsibilities. Party-selected experts are compensated directly by the party who selected them and communicate directly with counsel about details of the case, including potentially confidential information about the party’s case strategy. This terminological confusion demonstrates that at least some ambiguities about experts’ ethical obligations are tied to a failure to match ethical obligations to their functional roles. If they are functioning in a role (p. 173) that is not actually independent of the parties and their counsel, imposing an ethical duty of ‘independence’ does not provide any meaningful guidance. The question remains, however, how to define their obligations and enforce them.

4.95  Another purpose of an oath, quite apart from criminal consequences for perjury, is to promote responsible testimony by impressing on the witness the moral obligation of truth-telling. The effect of oaths on the truthfulness of testimony seems to be one of very few topics on which there is no expert. As one commentator notes, ‘[s]urprisingly, psychologists have never examined whether the oath affects witness’ sincerity’.¹⁸⁴ In the absence of direct testing regarding oaths, however, there is more than intuition to suggest the value of oaths on witness behaviour.

4.96  Social psychologists have done extensive testing of norm salience and its effect on behaviour. These studies have found some interesting results, which can be extrapolated to the context of witness oath-taking. For example, in one experiment students were demonstrably more cooperative in a game called ‘Community Game’, than other students when the same game was instead labelled ‘Wall Street Game’.¹⁸⁵ Social psychologists conclude from this and other similar studies that situational cues can radically change people’s mental state about what is normatively appropriate in a social context.¹⁸⁶

4.97  On the other hand, other experiments suggest that the potential benefits of such norm salience and norm compliance dissolve quickly when competing interests press on an actor’s immediate incentives. For example, in another study a group of religious ministry students were told that they were late for an extemporaneous talk across campus on the importance of helping those in need. Those ministry students tended not to stop and help a student lying in an overturned wheelchair. Their concern about being late overtook the norm of helping those in need, even if the potential speakers were undoubtedly considering precisely how to express that very norm at the same moment that they walked by the student in need.¹⁸⁷ These findings have potentially important implications for how oaths could be effective in adjusting the professional conduct of expert witnesses.

4.98  Cumulatively, the previously described studies about the effect of norm salience combined with earlier observations about the limitiations of oaths suggest potential reforms for international arbitration. First, traditional oaths seem to have limited value in deterring irresponsible expert witness testimony. They are usually framed in stark true-false dichotomies and administered moments before testimony begins. The risk is that an oath applied in this (p. 174) manner may be regarded as an empty and ultimately irrational cultural ritual. As a result, it may be all that much easier to disregard.

4.99  On the other hand, an oath or certification that is substantively meaningful and strategically imposed to provide a ‘situational cue’ could potentially have more meaningful effects. An oath has more potential to operate as a situational cue when it is connected to larger reforms similar to those implemented in Canada and New South Wales.¹⁸⁸ Those reforms enacted a ‘code’ or set of articulated norms regarding an expert’s obligation to aid the court in determining the truth. Those norms are provided to experts by counsel when they initially retain an expert as part of a code of ethics. The expert witness is then required to sign a certificate agreeing to be bound by those norms. These norms are framed in functional terms that seek to revise experts’ functional role by incorporating the oath into an expert witness’s professional undertaking. Oaths administered in this fashion also avoid the conventional true/false dichotomy that characterizes most oaths. Finally, to the extent the exercise is framed as a certification, it would appear also to avoid the prohibitions that some countries have against arbitrators administering oaths.

4.100  Like the religious ministry students ignoring a disabled student in need, it is of course possible that these norms may ultimately be ignored by party-selected experts. Nonetheless, having these self-regulated undertakings adopted at the beginning of proceedings, mutually acknowledged by counsel, and framed in more meaningful terms, make it more likely that they will become part of a process of acculturation into the international arbitration community.

4.101  Norms that are part of an acculturation process, as opposed to norms that are simply recited in an oath right before testimony is given, may be less readily discarded. More practically, early application will ensure they are applicable during the process of preparing reports and coordinating with counsel in anticipation of hearings. This approach to oaths may also put some pressure on counsel to restrain from putting undue pressure on experts to contort testimony. It is difficult, even for the most hardboiled of counsel, to participate in a process of communicating expert obligations and ensuring expert certification, only to turn around and ask an expert to blatantly violate the spirit, if not the letter, of those obligations.

4.102  In addition to using oaths to reacculturate experts, recently introduced structural reforms may help reorder the role of experts that make it inefficient or counterproductive to provide reckless expert evidence. The theory behind expert conferencing is that the effect (p. 175) of bias caused by attorney coaching can be diminished if experts are immediately confronted with the opinions and questions from peers.¹⁸⁹ As one commentator describes, ‘[P]eople are less likely to lie in front of their peers’ and other experts are able to ‘identify over-simplifications in expert testimony’.¹⁹⁰ In this sense, expert conferencing seeks to have immediate in-person peer review and provides a check on unethical excesses that vague ethical obligations with no meaningful enforcement mechanisms cannot.

4.103  Like using oaths as acculturation, witness hot-tubbing, witness conferencing, and expert teaming all seem to reorient the functional role of expert witnesses. These latter techniques expand expert witness functions beyond simply providing evidence in support of one party’s case to providing a direct check on an opposing witness. Some continue to doubt the efficacy of this new functional role¹⁹¹ while others appear to question whether functional roles can actually be reordered through these techniques.¹⁹² The growing interest and use of these techniques, however, suggests that arbitration specialists recognize that simply articulating ethical obligations for expert witnesses that have no means of real enforcement cannot resolve increasing concerns about potential ethical excesses.

4.104  International arbitration is still experimenting with expert witnesses, their functional roles, and their ethical obligations. While they suffer from some important shortcomings, the IBA Rules of Evidence are an important first attempt to regulate the conduct of experts. They clarify the distinction between party-selected and party-appointed experts, and attempt to delineate obligations attendant with each type of expert.

4.105  As procedural innovations become more entrenched practices, they will present new challenges in defining experts’ role and delineating the ethical obligations that attend that role. To that end, it is best to avoid the Frankenstein hybrids that combine expert witness functions (p. 176) with the role of advocates or the role of tribunals. These hybrids increase confusion about role and make it more difficult to determine proper professional obligations.

4.106  On the other hand, given the unique nature of expert witnessing, some of the best cures for the worst abuses require incorporating ethical reforms into structural changes that are directed at reacculturation in more carefully defined roles, such as the requirement that oaths be administered at the commencement of a case.