Conflicting Expert Evidence in International Commercial Arbitration : Means Available to Assist the Tribunal

The use of expert evidence in international commercial arbitration has continued to gain traction and is, in practice, considered a fixture of the procedure. It is, thus, undoubted that the role of expert evidence is significant. This role is strengthened by the fact that without experts providing the tribunal with specialized knowledge on empirical rules at issue, the tribunal is not able to resolve complex factual issues that are beyond its expertise. This study examines the means available to assist the tribunal in resolving issues of conflicting expert evidence in international commercial arbitration. It builds upon the crucial fact that the role of experts is to assist, educate and advise the tribunal, and that they are only needed for deciding on matters that are beyond the knowledge and expertise of the tribunal. Before addressing the research questions, the study aims to introduce the reader to expert witnessing in international commercial arbitration by considering the definition and the objectives of it, and by discussing certain leading principles such as party autonomy and the ability to tailor the procedure. Further, the role of the expert, the influence of both common and civil law traditions as well as the appointment of experts are discussed in brief. The principal problem and main question that this thesis aims to resolve is the following: What are the means available that assist the tribunal in disputes where expert evidence given is contradictory? The said main question is approached through two separate research questions that separately, but also in a mutually supportive manner, aim at resolving the core question mentioned before. The said questions are discussed under separate chapters, namely, the first one considering the procedural means (Chapter 3), and the second one focusing on non-procedural measures and the credibility of the evidence (Chapter 4). This division is made for clarity reasons and despite certain, inevitable overlapping of these themes. The first question seeks to define the procedural measures available that may be of assistance for the tribunal as it resolves issues caused by conflicting expert evidence. These measures are discussed under three categories, to say, the available questioning techniques, different approaches that have their ground in cooperation of the experts, and other innovative means. The first category is focused on two main techniques, cross-examination and expert conferencing. The second one, in turn, discusses the use of pre-hearing expert meetings, joint reports, exchange of draft reports and the Sachs Protocol. Finally, the third category considers, for instance, the use of single joint experts and arbitrator consultants. The second research question, in turn, focuses on the role of credibility and the non-procedural means available to evaluate this. This chapter as well is divided into three main categories. The first one considers the use of legal psychology as an assisting approach, whereas the second one focuses on the individual communication skills of an expert, both written expression and oral skills. The third one, in turn, presents different models on credibility assessment and elaborates on the issues with the existing, mainly procedural, means. This thesis aims not only to present and evaluate the use of different techniques, but also the recent trends in international arbitral practice. The focus of the study is mostly on party-appointed experts as the core issues with conflicting expert evidence are typically related to them. Further, as in most international commercial arbitrations the parties have agreed upon applying the arbitration rules of a particular institute or some other set of rules, this study has its focus on institutional rather than ad hoc arbitration