, in any event where an arbitrator has to be replaced during the course of the arbitral proceedings, a substitute arbitrator shall be appointed or chosen pursuant to the procedure provided for in that was applicable to the appointment or choice of the arbitrator being replaced. This procedure shall apply even if during the process of appointing the arbitrator to be replaced, a party had failed to exercise its right to appoint or to participate in the appointment.
2. If, at the request of a party, the appointing authority determines that, in view of the exceptional circumstances of the case, it would be justified for a party to be deprived of its right to appoint a substitute arbitrator, the appointing authority may, after giving an opportunity to the parties and the remaining arbitrators to express their views: (a) appoint the substitute arbitrator; or (b) after the closure of the hearings, authorize the other arbitrators to proceed with the arbitration and make any decision or award.