Had a "couple of people" been armed and began shooting... what are the odds that they would shoot one another... Or shoot people running and screaming. It sounds really Hollywood'ish to think you could, in a split second, determine what was happening.. who the bad guys are.. and who to shoot.. Suppose a "good guy" was also shooting from the other side of the room... WHO would YOU shoot? would you make the correct decision? Doubtful. NOW add a few more "good guys" ALL shooting at any direction they hear shots coming from. I contend that just as many people would have died in that concert hall.. only some of them at the had of the "good guys". It's utter NONSENSE to believe it would have made a difference.