The freedom of forms characterising arbitral proceedings permits the arbitrator to impose upon the parties time limits or evidential rules on pain of forfeiture, but not that this be done without prior and precise information to the parties as to the course thus given to the proceedings, and that rule applies to any requirement to which the arbitrator considers the parties’ conduct must conform with consequences for the proceedings.
The arbitrator may not declare inadmissible a pleading, an application or a documentary production for failure to comply with a time limit or a rule of conduct, where the corresponding conforming act had not previously been prescribed as necessary on pain of inadmissibility and made known to the parties in that light.
The rejection of applications for the taking of evidence in arbitral proceedings is in itself a potential ground of nullity of the award for breach of the audi alteram partem principle, an infringement of which also arises where one of the parties has been prevented, without justification derived from the legitimate rules of the arbitral proceedings, from setting out its evidence or from availing itself of the means designed to establish the merits of its case.
Under art. 830, co. 2 cod. proc. civ., where the setting-aside phase succeeds on one of the grounds set out in the first paragraph, the court must decide the case on the merits, making provision by separate order for the conduct of the re-hearing phase.