I've had a few professors who had this exact same attitude, although oddly enough the course had nothing to do with psychology or psychiatry. Anytime you asked a question or answered a question that someone else asked, the professor would agree your answer was correct but through obscure logic, it was actually done to annoy them. This would even happen if you pointed out there was a typo in the slide, the professor would quickly lose their temper and call you out because you called them out, even if you told them by e-mail or at the end of class.

I thought this professor may have an anger control problem but the DSM didn't have a category for what I thought the professor had: headupassitis or assholitis.