I agree it was strange, but I would like to hear if Chris Rock has an explanation why he chose to make that joke. He doesn't seem like the kind of guy who likes to insult people in a mean fashion.

It seems pretty insane to hit somebody on live TV and it sets a terrible precedence. While the joke was in poor taste, this is something that happens all the time in comedy. Not all jokes land well. I don't think standup comedians should start worrying about somebody in the audience getting offended and marching up on the scene to physically attack them each time they hold a show.

As a comedian himself Will Smith should know this. Comedy to a large part lives off mocking people, even if most comedians do they best to find a sensible balance.