Seriously... If i'm at a restaurant and someone busts in with a shotgun and starts blasting at people, i'm drawing. Easy as that. I do not believe I am Rambo or a cop or anyone to go beyond that.
I agree totally but with special note. If you are IN a situation, you should handle it if you can't remove yourself from it. You have NO BUSINESS inserting yourself into a situation to intervene!
The classic case is walking into a firefight, taking out a subject and finding out he was an undercover cop. OR How about walking into a fight, shooting the man and finding out the female subject was the attacker? OR, You pull the piece, the cops arrive at a "shots fired" scene and shoot you thinking you are the BG?
We are not trained for those things and the probability of screwing up is just too great.
Flash
I have nightmares about that last scenario. I truly hope nothing ever happens, and if it ever does, i'm not considered the BG and shot at.