Kathleen I understand your dilemma. My advise to you is to set your conversation. Number one the communication should be controlled. Understanding the emotion of this person there will be no discussion until the person writes down their concerns basing it only on the facts. Stopping and asking to write it down will lower the emotion. Asking the person to schedule a time to come see you. Set up ground rules for a productive discussion and when they are violated the meeting is over. If discussion is in the public at anytime they become unduly emotional they need to gomto your office and wait for you. When you arrive the start of the meeting should be to discuss how we could of better handled the discussion. Take this chance to revert back to going over earlier set guide lines