I say he's a punk and he probably won't try that sh_t again. But be careful, too.

I find I am a lot more assertive on my bike when I am commuting - I will stare down drivers that I don't think are paying attention and will point at one until he acknowledges me if I need to change lanes or move over to avoid something in the road. It works and I get a lot of space doing this, but that is different than dealing with someone that is giving you lip on the street. I've never had the problem, but still I think you did the right thing and probably helped some other riders out as well.

Good riding!!