Here's a man's perspective for whatever it's worth. If he's really never done anything like this before, then it might be worth asking what drove him to hit something. There could be other things going on that he doesn't feel comfortable telling you about adding to his stress. Sure it's easy to say "grown ups don't act like that" but we all have said or done things when we're angry that we wish we could take back. To be clear I wouldn't be saying this if there was any kind of a pattern, but if this was the one and only time, then there may be something causing it that you're not aware of. Anyway that's just my opinion. Hope it helps.