The answer to this question IMO would be... I'd like to think that most people would feel that their life is in danger with a BG with a gun in the confines of a classroom, especially when pointed at you.
But still, this brings up the question of why you, the good guy, had a gun in the classroom to begin with. I'm willing to bet that everyone in the classroom, except for the BG, would be extremely greatful that you were armed but I wonder what the radicals who were outside of the classroom and out of harms way would think...
Ultimately, I think there is no single correct answer to my question (if you don't see eye-to-eye with the current law) and that it all comes down to a personal decision.