One time when I was outside in the middle of the night two guys suddenly came up and pushed me to the street. I have martial arts training and they clearly didn't, but unfortunately I was wearing skates, which pretty much means that you can't throw punches or kicks. Worse, I had 400 euros in my wallet. Yeah awful preparation on my part, eh?
The leader of the two had pretty big hands and he made a fist and demanded that I give him all my money and if I didn't he would get out his knife. I made a quick calculation:
1. He's lazy, otherwise he'd work for his money
2. If he really had a knife, wouldn't it be easier to threaten me with it?
I took the risk of calling his bluff and told him that I didn't have any money.
Then he told me any amount would be fine, even 5 euros or less.
Another calculation:
3. He isn't going to kill for 5 euros
I told him I didn't have any money, this time pretending to be scared.
He told me to stop shouting.
I started shouting harder.
They left me alone.
In the gamestop case: I would have asked the guy who exactly has the gun and then judge from his reaction.
I guess my most likely cause of death would be calling a bluff when something isn't.