Touchy subject, but something that definitely needs to be addressed. First, I've never hit a woman and as the father of five daughters, I'm completely opposed to and disgusted by abusive behavior towards women. However, does that give women free rein to attack or hit us without fear of retaliation? If you're tough enough to throw a punch, you're tough enough to take one, as a friend of mine used to say about the matter.
I've seen the Rice video. Given the disparity in size and strength, his punch is clearly excessive and vicious. On the other hand though, she'd struck him shortly before and appears to be about to do so again. Is he supposed to just stand there and let her? Let's say it's a couple where the guy isn't a muscled up 230 pound professional athlete and he and the woman aren't very different in size. Do you just let her hit you? How about if she keeps hitting you? How many shots do you take before you hit back? I honestly don't have a good answer. I'm totally opposed to violence against women, but it goes both ways and nobody should have to take a punch just because the person throwing it is female.