Its all a matter of context. If a woman goes crazy and attacks a man, he should be able to defend himself. If she punches him for being stupid or something, he shouldn't just punch her back since "she did it first". All in the context of the event.
That is why religion is so biased. You do a bunch of other bullshit that is lots worse, but you can't do one of the things that is most enjoyable? Ridiculous.