Personally, I am glad that none of you wannabee Captain America types were there. 'Cause there would be one more victim, one more orphan, one more widow, and one more person this freak could add to his body count. It is one thing for a platoon of armed soldiers wearing protective masks, with supporting fire, indirect fire, and grenades to assault a positiion, a totally different thing for some unprotected goober without a clue charging across a dark theater full of obstacles, "sun" in your eyes, against the flow of a fleeing crowd, with snot and saliva streaming from your mouth like a calf slobbering, eyes burning like someone just threw lye in them, and every breath feels like breathing in fire. You'd have no force field, no mighty shield, no superpowers, no x-ray vision, no spider web flying from your wrist, nor would you turn green, large, and invincible.
Just a puny little man with .223 rounds cutting through you like hot butter. And they say that most soldiers ask for their mama in their dying breath.
Would have made a good movie though. And you might even be considered a hero....if you made it more than 10 feet towards the shooter.