Do people see a guy hitting a girl as a bad thing?

I know someone who has once said something about how no matter if it’s a girl or a guy, he would hit back all the same. Does anyone find that a bit harsh? I know we’re not living in the days of chivalry, but really, I like the “Don’t hit girls” thing. (then again.. is that even under the topic of chivalry? lol. i’m clueless. =\)
Understanding that if a female was brutally attacking a male, he would have to defend himself, but excluding that… Is there ANY time a guy hitting a girl is right?
where it has nothing to do with defense? I can’t think up an example. just want to see other ppl’s views on this.