When is it okay for a man to hit a woman?

Seriously. When was the last time that you heared about a case where the woman was the abuser?
When a husband hits his wife, tell me where the right in it. There are thousands of Husband hitting his wife, but how many cases there are where women hit their husbands? rarely, if theres any.

The wife usually kills the husband, that's why. (Sorry for the necro post)