Tbh, When you're both in a calm mood I'd have a word with him about appropriate expressions of anger - because this is not one of them.
I think people who go for the most hurtful, insulting comment they can in an argument thinking they can retract it later and you'll know it was "only because" they were angry have no idea about the effect of such a comment. It can chip away at the respect and trust until there is nothing left.
On the other hand, did he say it when he was angry because of something you'd actually done? Because there are some really shit mums (and dads) out there and sometimes they really do need calling on it, whether they want to hear it or not!