I also went to school in Brookings, and lived there for 6 years. There is no violent crime to speak of. 25,000 people live there, half are students, all of them get hammered on a regular basis. I'd be inclined to at the very least wait til I see a real threat, especially 30 minutes after closing time 5 blocks from where virtually all the college bars are. I don't necessarily blame the shooter, he was well within his rights, but...
I think that I'd likely have done the same. Incoherent drunken male starts kicking my door in at 2:30, even after repeated warnings......college town or no, closing time or no, I think that this guy acted properly.
No mention of family in the article. If the shooter had a wife and kids to be concerned about, no doubt in my mind he was in the right.