I have had a few over the years.
All of them were due to equipment in one way or another, but due to proper muzzle control no one was hurt.
My first was YEARS ago. Single action revolver. I was young and didn't know how light of a trigger pull it would take. I barely palmed the gun and it went off.
My second was a stuck firing pin on an old SKS I had. Apparently they are somewhat notorious for getting those, and I had a round that didn't chamber all the way so I tapped the bolt. It went forward only to fire the round in there and the one after it. I decommissioned that rifle after that.
The third was I was out shooting a pig, and the lever action I had, had a funky hammer. It slipped off my thumb when I was de-cocking it.
As I said in all cases, muzzle control was the saving factor.
I am thankful for my mentors who trained me well and instilled a healthy fear of firearms.