That's the way it's seen though. They will possibly see it as a) You aren't your property. and b) They brought the gun in case they ran into an issue, not to use it premeditatedly. They'll back that up by the fact that the unarmed guy was the one in the position to get shot, not the armed one. Of course the person doing the shooting will have to prove he was armed to begin with and asked why he didn't shoot the guy with the gun instead of the one that was unarmed. Phrasing a statement like 'if you could see well enough that he had a gun, couldn't you see well enough to shoot the one that was armed and "obviously" a threat' that will probably be enough to be a reasonable level of doubt in a juries mind to swing a verdict.