Sorry, I may not have been clear in my description. I didn't notice much of anything when he came in. It was after the interview started and he asked this question that he thought I answered incorrectly that the trouble started. That's when I started noticing the somewhat odd mannerisms and the fact that I couldn't get a technical discussion about the question started.
Like I said, I'm used to working with all types of developers. I usually get along well with my colleagues. I have no trouble with any kinds of quirks--I probably have some myself. The issue was that this person was not capable of running an interview. He couldn't deal at all with a minor conflict on a technical question. This kind of thing can lead to a company not getting good results from the recruiting process which is what the OP is about.
Like I said, I'm used to working with all types of developers. I usually get along well with my colleagues. I have no trouble with any kinds of quirks--I probably have some myself. The issue was that this person was not capable of running an interview. He couldn't deal at all with a minor conflict on a technical question. This kind of thing can lead to a company not getting good results from the recruiting process which is what the OP is about.