Thanks for responding, Tsunami. He asked to come to work with me this morning. We talked (i.e., argued) some more on the long drive to my job. Finally I told him to cool it, because he was upsetting me, and I don't want to fight with him in my office. He and I were both able to calm down and were even joking and laughing by the time we got to the office.

At this point I think my fears (and fatigue) were making me overreact to what he was saying.