Is there policy on intentional beer throwing at people?
Edit: I thought it was funny because of how "epic badass" the OP was trying to come across, plus the absurd lengths the commenters went to defend obvious antisocial behavior. Remove your reddit brainworms! The joke is not someone wanting their girlfriend to not be harassed, the joke is Reddit
Honestly screw it, I don't think the OP is really funny anymore, either. They might come across as silly due to being angry but who doesn't? Plus they're vegan, so, 
I've never been to a concert where this happens. Sometimes people will spin a cup of beer or something overhead and you get wet. That's generally in good fun, and part of the moment. but i've never seen someone deliberately throw a beer at a specific person. Most garage and house shows I've been to, doing that would get you carried out by very angry punks and possibly beaten up. Doubly so if the person you assaulted was a small woman.
Throwing at and hitting people repeatedly is some weird cringe shit idk why people think it's remotely reasonable. Of course accidentally hitting people while dancing is fine but throwing cups and cans at people has literally nothing to do with that
Right? Mosh in the pit. If someone's moshing and they're not in the pit throw them in the pit. If they don't want to be thrown in the pit, and don't want to stop moshing, throw them out. All the rowdy shows I went to back when I was cool, those were the rules. Do your thing in the pit, don't kick or throw punches, if someone goes down stop and get them up, don't be an ass, and keep it in the pit.