I think Sarge pretty much nailed it in post 48. Fade out, don't get involved unless you have to. Nobody is going to think less of you because you didn't jump in to a writhing melee and try to end it. Nobody is going to think less of you for not trying to shoot it out with some guy shooting up a crowd.
Your CCH permit does not make you a cop. It does not make you bullet proof. What it does is let you carry a gun in public. That is all it does. Unless yo are a LEO don't try to play the role. They get paid for it, they have the training for it, they have balistic vests, and they have a lot more lawyers to back them in whatever happens.
Survive. Then you can go home and kiss your family or pet your dog. Becoming a dead hero does nobody any good.
Here's my credo: There are no good guns, There are no bad guns. A gun in the hands of a bad man is a bad thing. Any gun in the hands of a good man is no threat to anyone, except bad people.