It isn't LEGAL to carry a gun on your person with bullets in it anyway, unless you live in Texas. You can carry a gun in your trunk, and the bullets in the front seat, so either way you're fucked. You just have to hope a jury feels you were in the right, but they'll probably send you away for a bit anyway for carrying the damn gun in the first place.
And yes, it is ho shit to shoot somebody in the back, but it's also ho shit to pull a gun on somebody period unless it's for defense purposes. So, if somebody pulls a gun on you to take what's yours, that's a threat on your life, sometimes even if you cooperate. If you pull a gun on somebody, you better squeeze it, if not, then the victim has every god given right to shoot your ass no matter which way you're facing. You weren't expecting a gun to your face, they weren't expecting bullets to fly towards em, it's all fair game. Sometimes people believe that is the only way. If I were gonna squeeze on somebody like that, I'd make him turn around first, some way, I'd get him to turn his ass around.
I had a gun pulled on me when I was 9 years old, for NO REASON. Dude thought he was funny. I still think about that to this day, and how that made me feel and how it affected me long term. I wouldn't do it, but sometimes I wish I could see dude and shove an HK in his face, and laugh at him like he laughed at me when I was 9.