RWK, no criticism meant of you. I knew what you meant, and I'm sure you would have said that you would not fire or precipitate any violence if the store was full of people, the BG didn't fire or seem agitated enough to fire, and it looked like he would walk out.
I'm referring to the occasional visitor (this being the 'net and all) who may have a 'kill 'em all and let God sort 'em out' attitude. Very, very rare on TFL, thankfully.
Ron, glad you see our perspective. Thank you.
Regarding the question, the best advice I've seen about the situation above is that you must try and gauge the likelihood of the BG killing you or someone else. Pretty tough.
Action beats reaction. So, if you hand is on your revolver, then, theoretically, you will be able to draw and fire before your assailant. But, that's the first shot or two ... You could miss. If he has a shotgun, you're facing a lot of firepower. (We've seen this in Phoenix lately, in convenience stores ... imagine you're looking down the short barrel of a shotgun. That'll focus the mind.)
If there are customers in the store, it becomes more complicated still. Are they behind the BG? If so, then there is very great danger that you will hurt or kill them if things get ugly. Your best bet then, if absolutely necessary, is to try to drop low and fire up, so that overpenetration and missed shot(s) hit the ceiling. If customers are well off to the side or in the back of the store, then this risk is reduced, but not eliminated.
Someone may correct me, and I don't know the stat's, but most armed robberies end with no shots fired. I think we all owe a moral duty to ourselves, our families and our communities to stop scum like this BG, if legally and morally justifiable. But, we can't do so by foolishly endangering innocent others.
So, it comes down to the location of innocent others, your confidence with your firearm, the look in that scumbag's eyes, and the hairs on the back of your neck, IMHO.
And, I hope none of us ever have to work this difficult calculation.
One last point, about reviewing scenarios like this. Some folks make the correct observation that in a real situation like that above, all these fine points of discussion go out the window ... rather like the fog of war. To a great extent, I'm sure that is true. But, I still think it helps to consider self defense scenarios. For example, I asked my sister what she would do if a BG forced her into a car, and told her to drive him somewhere ... while holding a gun on her. She immediately said she would do 'whatever he tells me to do'. I told her she would die. I advised her to have her seatbelt on, and drive into the nearest hard object, like a bridge abutment or telephone pole ... preferably with the passenger side of the vehicle. And get the he!! out of the car as quickly as possible after impact - she knows the impact is coming and the BG doesn't. Traveling to a secondary crime scene is often the end for victims. There is no question in my mind that my sister and wife would take similar action now, but only because they've heard it from me and others. I strongly believe there is value to considering these potential incidents before they occur.
Thanks for the exercise.
Regards from AZ