Defending Yourself Against and Even Hitting a Woman?

Not a nice topic to bring up I know, and no, this doesn't involve me. But one of my best friends, who is a woman, and I had this conversation yesterday.

My friend is a substitute teacher and was subbing 4th grade last week. One of the issues she had to deal with was a girl in her class pushing a boy, and the boy hit her on the shoulder and pushed her back, hard enough to where she fell on the floor.

Of course it's only the boy who gets in trouble, as my friend had to call the assistant principal. The boy defends himself and tells my friend and the assistant principal "my dad always tells me to defend myself, boy or girl, it doesn't matter" and "someone hits me, I hit them back".

Of course. my friend is just stunned that a father would say this. My friend is conservative and in her mind hitting a woman in any way is a big no-no.

But am I wrong for kind of understanding what the father is saying? To me it goes back to selective equality. Women want equality unless the old traditional ways benefit them. One of those is the idea of hitting (or shoving, or any physical action) a woman. It's made a lot of modern women really arrogant against men, knowing that man simply can't respond.

Luckily we're good friends so we didn't get into it, but I did flat out say that if a woman hit me (emphasizing hitting with a closed fist, not just shoving), I'm hitting back in self-defense.

My mentality is obviously a man should never proactively hit or shove a woman. But if a woman goes after you, including hitting or trying to hit you, do you consider it appropriate in our current society to hit a woman back in self-defense?