Not to sound rude or unsympathetic, they were dead either way. If you were going to get shot and killed would you rather it be by a crazed gunman or a friend trying to protect innocent people? For that matter, you are dead. I don't think you care who shot you.
The fact is, even with the possibility of panic, the odds of this being stopped before it reached the point it did is quite good. We aren't talking about handing out guns to every student on campus. We are talking about CCW holders (which my assumption would be a very small percentage of college students/teachers) being allowed to carry just like they are everywhere else.
I'm sorry but in that kind of situation I would rather go down in a fight than be cowering for my life.