This is very odd that Venezuela would try to disqualify their own arbitrator during the hearing. My guess is that he was sounding opposed to their case. The only legitimate grounds would be that he has become unable to do his duties, since Venezuela nominated him.
The other two arbitrators will decide, and I would think fairly soon. There are some best efforts to decide within 30 days language if it is done by the Chair of the Administrator Council, where it should not be here -- the other two arbitrators should have that duty, but it indicates that it is expected to be decided with expedience. Nonetheless it is a delay, but if decided against, the panel could push other dates up to compensate for the time lost.