While working in a retail establishment, I too had a gun pointed in my face. It was against policy to have a gun in one’s possession at work, so there was nothing to be done except to try and survive. Not a very pleasant moment. If I were to have shot the perp, would have been fired.
Firefighters are not allowed to carry guns either. I once had a psycho who called 911 saying he was having a heart attack point a semi-auto hand gun at me at close range and start pulling the trigger. All I could do was quickly exit and my co-workers and I armed ourselves with axes until the police arrived.
The police told me later that the idiot had put the cartridges in the magazine backwards. There are of course more humorous details about the event... his goal was to ambush some first responderes and then shoot himself.