These guys are so lucky no one was hurt.
This is why you treat every weapon like its loaded, and you always point it down range.
If there were two rounds on that gun, he easily could have jerked the trigger on the recoil and killed someone next to him or behind him.
Be careful, be safe, treat every weapon like its loaded, and don’t put your finger on the trigger until your siting down range. Using a safety is also good practice, but it really is the last resort in safe gun handling.