SXSW Bully sucker punch. Justified or cheap?

Dude deserved it and I'm glad he got it. But the dude who punched him was a little too opportunistic for my tastes.

He apparently had nothing to do with the original situation and was just looking for a perfect place to hit someone without actually being in much danger himself. That's kinda wussified in its own right.

But I don't really care all that much. Just probably wouldn't be friends with a dude like that.