Im not going to defend the joke because it was poor, but the response wasn’t warranted.
You can’t physically assault someone like that on account of a joke. It didn’t show courageousness, it showed weakness on Smith’s part. It didn’t show wisdom either, it showed pure impulsiveness and an inability to control one’s self. It didn’t recapture his wife’s honour either, it had actually made what would have been a forgettable moment something that will be remembered forever, and not in a good way.
He could have confronted Rock and demanded an apology for example. But to default to physical assault, that only serves to reflect badly on Smith. You can’t set a precedent where it’s ok to assault comedians either.