Gun ranges are scary because you don't know how safe the other people on the range are. It's even worse when you can't rely on the employees to follow the rules.
Bringing a gun back without it being checked reminds me of an experience I had at Metro MANY years ago. I was young and the Desert Eagle was pretty new. I had gone to Metro and rented a .44 magnum Desert Eagle and a box 20 shells to try it out. The thing was massive. I literally only put one round in the magazine just to see how the recoil was. I had visions of putting rounds into the ceiling from the recoil. After I finished shooting, I brought the gun back to the counter and handed everything back to the young woman working the counter. She asked me if I would mind pulling the slide back to show her the chamber was empty. I thought it was odd but went ahead and locked it back and showed her it was empty. She thanked me and said that she wasn't strong enough to pull the slide back on those. She said just recently they had a customer rent a gun and they brought it back to the counter with a live round IN the chamber. She said they had to be very careful now and check every gun that comes back to make sure there isn't a round in the chamber. Scary stuff.