It's just another form of the common street robbery. The only difference being the reason he was targeted and the item they wanted. The obvious issue is how do you disguise your draw when they know you are armed, where your weapon is, and are focused on it. I don't have a good answer on how to beat a drawn gun in those circumstances.
Or more armed citizens. Rob one, 2 others draw.Concealed BUG would be helpfulness that situation.