Show them the "Dear Woman" video. Be perfectly neutral and simply ask them "What do you think of this video?" If a woman replies "How sweet, apology accepted, what a great world that would be" etc, like I've noticed for quite a few comments on that video, you've got yourself a genuine 100% certain man-hater. If a man likewise says "I agree, yeah we should be more like that" etc. you've got yourself a self-hating white knight wuss.

I know I'm kinda half joking, but it's an interesting thought.