No. Only referees assigned by the home association can ref league or home exhibition/tournament games.  There is a Hockey Alberta rule that if no refs show up, both teams are to agree as to who will ref the game until referees arrive. (the person needs to be on onw of the teams HCR roster).  For SAMHA games please contact the referee assignor or referee in chief in the event there are no refs at your home game, so they can follow up with the ref that is absent and try to arrange for someone to attend the game.