The liability of an arbitrator pursuant to Article 813-ter of the Code of Civil Procedure, which refers to the parameters of liability of judges under Article 2 of Law No. 117 of 13 April 1988, does not exist when the conduct complained of is attributable to the interpretation of rules of law, even where such interpretation has resulted in an award subsequently set aside for formal defects, where the legal framework applicable to the case is characterised by objective uncertainty arising from successive legislative regimes over time and from the absence of clear indications in the arbitration clause.
Serious fault on the part of an arbitrator, understood as manifest breach of law within the meaning of Article 813-ter of the Code of Civil Procedure, must be excluded when the appointment of the chairman of the arbitral tribunal was made in the reasonable belief, shared by the other members of the tribunal and not challenged by the parties during the proceedings, that the applicable rules did not require particular formalities, in a context of objective uncertainty as to the applicable regime.
In assessing the existence of serious fault on the part of an arbitrator, the threshold of care required must be measured also against the specific professional competence of the person invested with the arbitral function, and it may be relevant that the arbitrator lacks specific legal training where the disputed question concerns the interpretation of procedural or substantive rules of law.
An action for liability against an arbitrator, whilst presupposing the successful challenge of the award by judgment which has become final pursuant to Article 813-ter, paragraph 3, of the Code of Civil Procedure, requires an independent determination of the existence of serious fault, which cannot be automatically inferred from the setting aside of the award for formal defects.