Article 190(2)(d) of the Private International Law Act (PILA) provides that an award can be challenged if the relevant arbitral tribunal has violated a party's right to be heard.

The application to the Supreme Court related to a dispute between the European Chess Union (ECU) and the applicant, a national chess federation that was looking to host two ECU tournaments. The organisation of ECU tournaments involves a tender process in which national chess federations within Europe propose one or several host cities. After the applicant and several other federations had filed their proposals, the ECU, pursuant to its rules, designated an inspector to evaluate the proposed cities. The ECU then awarded one tournament on the basis of the scores allotted to each city. Further deliberation by the ECU was required in relation to the other tournament as a result of the overly small gap between the proposed cities' scores.

The applicant failed to be selected for either tournament. On grounds that are not explored in the Supreme Court's decision, the applicant subsequently initiated a CAS arbitration and requested the arbitral tribunal to order the ECU to award it both tournaments or, alternatively, initiate a new tender process for each tournament. On 22 March 2012, the arbitral tribunal rendered an award rejecting the applicant's claims.

During the arbitral proceedings, the applicant requested the arbitral tribunal to appoint an independent expert who would be tasked with evaluating the cities that had been considered by the ECU, enabling him or her to then determine whether the ECU inspector's own conclusions were indeed defensible. The tribunal rejected this request, finding that "no grounds have been put forward or established which justify the appointment of such an expert by the Arbitral tribunal". In so doing, it reminded the parties that they were nonetheless free to nominate their own experts pursuant to the CAS Code. At no time thereafter did the applicant raise any objection to the arbitral tribunal's decision. However, shortly after the tribunal handed down its award, the applicant filed a request with the Supreme Court to have the award set aside, contending that the tribunal's refusal to appoint an expert had violated its right to have its case heard.

The Supreme Court quickly rejected the application on the grounds that the applicant had failed to raise this argument during the arbitral proceedings. The Supreme Court once more confirmed the established principle in Swiss case law (as well as many other jurisdictions) that any perceived violation of a party's procedural rights must be brought to the attention of the arbitral tribunal immediately, when it is still in a position to consider an objection on the matter and change its mind accordingly. Omitting to do so, but nonetheless relying subsequently on such a violation to challenge an award, is contrary to good faith.

Despite the outcome of the case being clear, the Supreme Court took the time to sympathise with two arguments advanced by the applicant. The court noted that any "ad libitum" (that is, discretionary) dismissal of a party's request for a tribunal-appointed expert, where such an appointment could result in evidence proving a pertinent and contested fact, may well constitute a violation of the requesting party's right to be heard. This right can be violated even if the procedural rules governing the arbitration provide that the power to appoint is at the arbitral tribunal's discretion. However, the Supreme Court did not discuss the matter in great detail and failed to articulate which elements of the arbitration in question actually gave rise to the need for a tribunal-appointed expert in order to ensure the parties' right to be heard.

On a related point, the Supreme Court also objected to what it perceived as the arbitral tribunal's apparent assimilation of the evidence of tribunal-appointed and party-appointed experts. The rules governing the two types of expert evidence are very different. Furthermore, the probative value of expert evidence presented by the parties simply cannot compare to the opinion of a tribunal-appointed expert.

The Supreme Court arrived at its decision in routine fashion, relying on the applicant's failure to object to the supposed violation during the arbitral proceedings themselves. Interestingly though, the Supreme Court's contention that the arbitral tribunal's refusal to appoint an expert was a violation of the right to be heard, challenges the discretion that arbitral tribunals are often perceived to have in exercising this appointment power. The CAS Procedural Rules themselves state that an arbitral tribunal, "if it deems it appropriate to supplement the presentations of the parties, [...] may [...] appoint and hear experts" (emphasis added). Almost all other sets of arbitral rules (including ICC, LCIA and Swiss Rules) take the same approach. In that regard, the decision, which confirms previous case law of the Supreme Court, implicitly states that the lex arbitri may modify such arbitral rules to limit the discretion afforded to arbitral tribunals in the exercise of the power in question.

Swiss lex arbitri, as developed by the case law of the Supreme Court in particular, does indeed impose certain limitations on discretion for cases in which relevant facts concerning technical or other issues require special knowledge in order to be proven. Where the arbitrators do not possess such special knowledge, an arbitral tribunal will violate the parties' right to be heard if it rejects a timely and formally valid request for a tribunal-appointed expert (Decision of Federal Tribunal (DFT) of 28 March 2007 (4A.2/2007), cons. 3; DFT of 16 October 2003 (4P.115/2003), cons. 4.2, partially published as DFT 129 III 727).