That's definitely a factor, but seems surmountable with a modest amount of training for the proctors. You also want to watch out for proctors that have an unusu

That's definitely a factor, but seems surmountable with a modest amount of training for the proctors. You also want to watch out for proctors that have an unusually high/low pass rate. You might go as far as being strict with them about what hints are permissible, and/or audio recording the whole session to see what hints they had (and also to impartially evaluate soft questions). I would say it's still an improvement over leaving the whole thing up to the whims it the interviewer.