I would have shot him outright.... soon as he goes down, or his weapoin is dropped... I'm getting Fred and myself out of the store and calling 911 from the payphone outfront, or the cell phone. I'm staying put unti authorities arrive, and willingly surrender and cooperate.

Soon as that weapon is dropped, or the robber is incapacitated... threat is removed. If he dies... he does... if not... good for him... I'm alive, so is Fred... mission accomplished.