Taking the riskThe purpose of sounding Captain Obvious, let me point out that the purpose of an interview is to determine if a candidate is a good fit for the joban interview is to determine if a candidate is a good fit for the job. If your interview panel does not have sufficient confidence that the candidate is suitable, do not extend him an offer.
Several factors can, and do, go into making that decision, not just their technical competency. Several factors go into making that decision, not just their technical competency. Weirdness is one such factor, but there are plenty more. I have seen technically well-qualified candidates getting rejected, because they were "too much into research and not into business", their communication style was extremely convoluted, they worshipped a platform that we don't use (you know, the Java v/s C++ problem), their showboating was way over the top, and so on.
From your description, it sounds like communicating with women is important to this jobCommunicating with women seems important to this job, and John has made it clear that he is far off the mark there. So naturally, you can conclude that the candidate does not meet the requirements.you can conclude that the candidate does not meet the requirements.