A long time ago at a local outdoor range was a gentleman shooting a S&W Model 49 Bodyguard -the one with the shrouded hammer- whilst sitting in a folding chair at the range table. No problem... except that he took to firing single action and he would bring the gun up next to his ear, muzzle pointed
behind the firing line while cocking it. The RO was busy at the far end of the rifle line so when the guy started to raise his hand, I blocked it. I crouched down and informed the gentleman of his error, why it was a safety issue and to please keep the muzzle downrange. To my surprise, he went ballsitic because I was not the RO and told me to mind my own Mo-Fo'n business. When I told the RO, he said "Serves you right for buttin' in." ***? I never went back to that range.
A couple of years ago someone had a 7.62 Tok chambered CZ 52 at the range. I didn't directly see the action but figured it out from the after-action mess. The safety wasn't and our nimrod shooter decided to let his brother try the gun. He points the gun sideways--down the line-- and pushes down the safety. *KerPow!" Five lanes to the guy's left a revolver flies through the air and everyone is jumping back off the line. The wheelgun owner was extremely tee'd off and headed right for the guy. Lots of bodies calming people down. The 7.62x25 round whizzed past 3 occupied & 1 empty lane and struck the shooter's 1968 Colt Python right at the base of the front sight. Sight gone, barrel rib fractured and the end of the barrel distorted. The CZ shooter ended up buying himself an $1800 ruined gun and being asked to leave the range.
When California implemented it's first training program for security guards in the mid-70's, some of their contract instructors were barely qualified to grind garbage. One such manure-shoveller insisted that the lands & grooves inside a barrel were there, not to impart spin in the bullet but "to let gasses blow by the bullet, otherwise the barrell will explode". ***? Same guy claimed that a barrel would wear out in 5,000 rounds and reqiure factory replacement. Several of us called him on this misinformation and he reacted as if we'd suggested his parents had never married.
At the range session, he told us to shoot one-handed because "a two handed hold will get you killed."
After the class, I got enough people to write complaints to Sacramento that they tightened up on the instructor qualifications.