The Swiss Supreme Court has rejected a challenge for violation of the right to be heard, which was based on the tribunal's refusal to appoint an independent expert. By doing so, the Supreme Court clarified that, in principle, the appointment of a tribunal appointed independent expert is a right of the parties. However, that right is subject to certain conditions. In the present case, these conditions were not met, which is why the refusal to appoint an independent expert was not in violation of the petitioner's right to be heard.

It is noteworthy that the court emphasised that parties must make express requests for the appointment of an independent expert, in order not to forgo such right. Moreover, the court appeared to add a new requirement that parties submit the core documentary evidence on which the expert opinion will have to rely, together with the request to appoint an expert.

Finally, the court explained that its power to review the tribunal's appreciation of evidence from the viewpoint of a potential violation of the right to be heard is very limited. In fact, the right to be heard is only violated, if the refusal of a tribunal to admit evidence has a potential influence on the tribunal's decision. Without such influence, the Supreme Court held it cannot revisit the tribunal's decision in this regard, thereby qualifying its power to review. (Decision 4A_277/2017.)