Wow! That guy with the revolver is lucky. If the timing of the gun is off or there is some defect in the bullet, then rather large lead shavings will fly through that gap to cause a pretty serious injury to the hand. In any case, if it was, say, a 357 magnum, the pressures are high enough so the gas can damage the hand.
I've had quite a few strange things happen at the range, I'll just give a few:
1) A man died of old age while we were both shooting there one Sunday morning. Nice fellow. Nice family. He was elderly and just passed away doing something he really liked to do. He and I were the only Sunday morning regulars there. Technically it was heart failure, but he had just put his head down like he was taking a nap and was gone. Very peaceful. Quite shocking too when I thought he might not be napping.
2) Some Russian guys wanted to become members so they could shoot at the range. I made sure they got the info they needed so they could join. These guys had a ball with their shooting. They had bought some Mosin-Nagant ammo, lots of it, and a rifle to shoot it with. They were having a great time shooting targets and sharing the gun. I've never seen three guys have so much fun shooting. It was a flash in the pan, though, I never saw them after that year.
3) I learned something through experience during the Fall sight-ins (when the range is open to the public for deer season sight-in). When somebody comes to the range with the gun in a cardboard box, watch that person. These are the guys most likely to have a safety infraction.
4) There was a guy shooting a 44 magnum Ruger Blackhawk from the seated position, using sandbags as a rest. He was obviously afraid of the gun. He touched a round off and the hammer hit is forehead and cut it. Thankfully we had some bandages and disinfectant.
5) Then there was the time when we had a plague of woodchucks under the range house. I had the range to myself and I was there with my bullseye 45 shooting them. Muzzle was pointed downrange, but not from by the benches, but from the parking lot. They are tough critters. The target 45s are not good stoppers on chucks. 22 hollow points are better, in my experience.
6) I was at the big public range at Casper, Wyoming sighting in for a pronghorn hunt. This big pronghorn buck climbed up on the berm at the 300 yard line. That helped me judge the size of a pronghorn at that distance.