Yes .. provided the arbitrator does so in the presence of the opposing party. When I trained commissioners, I advised that at the beginning of an arbitration they ask the parties if they are inexperienced and if so spend some time explaining the process to be followed and basic rules of evidence. Where I suspect one or both parties are inexperienced, in dismissal cases for misconduct and incapacity I go through the elements required to prove their case as per Schedule 8 of the LRA .. on a flipchard, if one is available!!