I'd Argue that a Crowd* of that Size...

...against one person is a deadly weapon. Apparently the local cops agree.

“After reviewing the evidence, which includes surveillance video and witness statements, we have determined the individual … acted in self-defense upon being surrounded by a crowd and attacked by some of those individuals,” according to the statement.

It could also be argued he could have avoided the whole mess by staying away. Also, you fire a shot in the air it's gonna land somewhere and I'll leave it at that.

*of "mostly peaceful protestors"