The part of an arbitral award in which the tribunal applied of its own motion a reduction of damages for contributory negligence of the creditor pursuant to Article 1227 of the Civil Code is partially void under Article 829(1)(9) and Article 830(1) of the Code of Civil Procedure, where the tribunal failed to submit the relevant issue to the parties for adversarial argument, thereby preventing the challenging party from adducing evidence, producing documents and critically reassessing the evidentiary record on the specific fact attributed to it.