Good for you. And I'm sure you realized every time, that you bore some liability for the gun, having loaned it to somebody outside your supervision. It's part of why I never lend guns out, and even when I shoot at the range, only friends and family (that I trust) get to handle any of mine. I once had some fed cadet come up to me and drool over my new HK and ask to shoot it. He had his laminated card and the haircut, no reason not to trust that's who he was. But I said, sorry, no- I don't do that.
Asshole #1 is Davis. His teammate, the guy who who had Miller give him his gun, is this guy, Miles. HE is Asshole #2:
I'm not sure why you're bending over backwards to defend these assholes. Unless you want to go with the crazy story that Miles snuck the gun into Miller's car without his knowledge -- and then hand-delivered it to him when asked, just before a gunfight over a girl's number.