I hope the guy is OK.
My Dad got me a BB gun when I was 2, a pellet gun when I was 6 and a 20 gauge pump when I was 8. Though I really don't shoot that much anymore, I shot a lifetime worth of ammo before I finished high school. I've always practiced gun safety and got on those around me who weren't.
One time, I went shooting with a co-worker. This was back in the early 80's. He had his two young kids with him and we were standing along a tree-line behind my house and was getting ready to head in to shoot for awhile. At that time, all of my guns were strictly hunting style firearms. He had a pistol grip 12 gauge with a sling and handed it to me to fire off a couple of rounds. I checked the safety and then slung it over my shoulder.
I about died when the gun went off behind me. There was a large hole less than 6 inches from my foot. I quickly glanced at both his kids to make sure they were OK, then looked at him. I took the gun off my shoulder, pointed it away and down and carefully unloaded it. I handed it to him and told him to destroy it.
It was the only shot fired that day and I never, ever forgot it. Everything I did that day was safe, yet there was still an unintended discharge...and there were kids present. To this day, any chambered firearm in my possession is not only pointed in a safe direction, but I can see both the muzzle and the trigger. If there is a round in the chamber, I won't sling the gun.
It literally scared me in many ways and became a life lesson. I'm not saying all should practice this personal safety "quirk" (kind of defeats the purpose of a CHP), but I can honestly say that I will never, ever have a chambered firearm around that I cannot see both the trigger and muzzle.