I would suggest telling the interviewer that you would listen to the criticism, and apologize to the parent. This shows you are not stubborn, and capable of listening. Even go as far as asking the parent how they feel their child should have been treated, and say you will do your best if the situation comes up again. If you feel, you were absolutely correct in how the situation was handled, and the parent simply is unaware of the actual events that transpired, maybe it would be best to ask a fellow counselor assist you as you explain the situation to the parent.
