Someone got punched at a party at an Irish pub? Bet that never happened before. 
In Ireland itself, I'd say it's pretty common. But it's mostly the younger people who seem to be the most violent. When I was there with some friends several years ago, for some reason the drummer in the house where we were would keep getting jumped by a group of teenagers on his way back from the convenience store. They would punch him and spit at him for no reason at all. His was tough enough to handle it okay, though. I took that same path many times over a period of several months and I never even saw them once, though. As for pubs, I never had any problems with those, either. But there are lots of pubs in Dublin, way more than I would ever be able to keep up with.
