(Direct link so you can get past the stupid kids' comments) Here they say he was some random exhibitor at the expo, who got pissed off with everyone 30 seconds before the stream started. After what's on video he tried to hit redeye and did hit carmac (ohnoes). No charges pressed, still working at the expo like nothing happened.
Bad damage control from the caster. His primary objective should be to get that guy out of the shot as fast as possible, no to win some ego fight. He should have said something like: "Oh I'm sorry, not meant personal, just joking to the audience because you were in front of the camera" or something like that. Actually, he shouldn't have called him an idiot in the first place (even if right) and just ignored him considering what went on beforehand. Might still not have worked, but enticing the guy further is certainly not going to work. Then again, it was probably better entertainment than anything that followed, dunno. ;)