Fun mental exercise: They've got those "shoot a machine gun!" businesses in Las Vegas. People pay a bunch of money to have someone help them shoot different guns. I had a rich friend reserve a special VIP session at one of those places for a bachelor party, of which I was a part. It was a weird experience because while you get to shoot stuff, they don't let you load any of the weapons, and when a magazine is empty, there will be a guy hovering over your shoulder who will snatch the weapon from your hands, quickly remove the old magazine and replace it with another one and chamber the first round for you if need be. It felt wrong to not have complete control over the whole thing, but I guess if someone doesn't know what they're doing, this is how they help with that.
In this case, a client is basically paying someone to be the gun expert so they can play with guns. If a patron of that business(who knows nothing about guns, but is paying to get to shoot them) accidentally shoots someone with a weapon they thought was not loaded, is it their fault? Or the fault of the business? If it's the businesses fault, how is that different when it comes to an actor or producer paying an armorer to setup weapons for a shoot?
Fun anecdote: when we first had a safety meeting at the beginning of the session, the lead guy asked "Who is going to be my problem guy here?". We all assumed he was asking which yahoo was going to try to use their tommy gun to write his name in craters in the wall of the range, so we of course all pointed to the bachelor who was vibrating with excitement. We didn't realize he was asking who didn't know how guns work, and we also didn't realize that we had one quiet dude in the back who actually didn't. I've never seen anyone whiskey throttle with a weapon before that, but this guy kept his finger on the trigger of an M249 as he fell over backwards from the recoil and managed to shoot their target retrieval system right off the ceiling while we all hit the deck. That was a hell of a thing.