Most people would probably go into shock when they are being shot at. I know this because I used to be in gang fights where 20 guys tried to jump me. I pull out my pistol and all 20 of them ran like little school girls hiding behind cars and tree's. Now this guy started shooting in the classroom with no warning and NOONE charged at him to try to stop him because everyone was all scared shitless. Noone tried to sneak behind him to stab him with a pencil or anything. You guys act like your all brave and say u would have done something if you were in those students situation. Im telling you right now, your going to be different when your acually in the situation.
QFT! Nothing will ever prepare you for the first time someone levels a firearm at you. I can tell you the first response is not to act. It makes you shut up real quick in order to best examine the situation, preceded of course by a pucker reaction.