An expert witness obviously should be thoroughly prepared to give oral testimony in an adversarial proceeding, and frankly that can best be done by counsel. Is that always permitted in international arbitrations? (This is part of a series of posts and articles offering advice “from the trenches” concerning the use of experts in international arbitration.)
Institutional arbitration rules are largely silent about this question. Occasionally, they expressly permit witness communications with counsel. Thus, in a few instances, witness “interviews” by counsel in anticipation of testimony are expressly permitted by applicable institutional rules. See, e.g., the commercial arbitration rules of the London Court of International Arbitration (“LCIA”), Art. 20.5 (subject to applicable laws); and of the Singapore International Arbitration Center (“SIAC”), Art. 25.5. More broadly, the institutional rules do not expressly prohibit the preparation of expert witnesses by counsel either. As a practical matter, in the absence of detailed prescriptions by the arbitration-administering bodies and in the interest of certainty, this procedural point may have to be agreed by the parties and/or ordered by the arbitral Tribunal.
That said, one must also be mindful of the controlling procedural law of the arbitration. Absent specific agreement by the parties, that is generally the arbitration law of the chosen place of arbitration. Thus, the LCIA’s note that its rules are subject to applicable laws indicates a normative principle — that the law of the place of arbitration may determine procedural issues and should be examined closely.
For example, if the situs of arbitration is in England, and local law governs, it may be argued that the Bar’s Code of Conduct (affecting barristers), which prohibits rehearsing, practicing or coaching a witness, and the Solicitors’ Code of Conduct, which prohibits “misleading” a Court, apply to limit U.K. counsel’s contact with trial witnesses. English solicitors and barristers generally assume on that basis that preparation of any witness to give testimony in an arbitration hearing is improper as well, although that is not due to any provision of the English Arbitration Act (1996). Indeed, English lawyers generally consider it unethical for them to prepare any arbitration (or litigation) witness to give testimony in any jurisdiction.
Furthermore, the rule in the U.K. is that even the orientation of a witness to the procedures for giving oral evidence is not to be conducted by someone having personal knowledge of the matters in issue in the case in which the testimony is to be given. That rule was adopted in the Bar Council’s Guidance for both civil and criminal proceedings based on a decision by the Court of Appeal in R v. Momodou  EWCA Crim 177 (par 64), a criminal case.
Finally, if preparation of expert witnesses by counsel to give oral testimony is permitted by agreement, by order of the Tribunal, by rule, or by law, counsel should also bear in mind that communications with an expert witness are not privileged.