This is why when you close a shotgun you bring the stock up to the action not vice versa. This is one of the many points on gun handling mentioned on our shoot.
It happened a week ago, gun went off, blew a nice hole in the ground. Man went home with just the one sock .
Diagnosed as a stuck firing pin.
I think that break open shotguns and DRs, while they have many excellent virtues, are more dangerous than bolt rifles. Especially if the bolt gun has a three position safety.
The SxS or O/U shotgun/rifle is SOMETIMES equipped with an intercepting sear that will interrupt the fall of the tumbler (hammer) if the main sear is jarred out of the bent. This means that the gun cannot be fired unless the trigger is pulled. However, the vast majority of shotguns do not have this feature and rely only on a simple trigger locking safety catch. As pointed out in a couple other posts, break open guns can fire on closing and on heavy recoiling rifles firing one barrel may jar loose the hammer on the neighboring barrel resulting in 'doubling'. The design of most single triggers on double guns is often problematic as well and accidental discharges can and do happen.
When bird hunting the danger is multiplied - dogs, hunting partners, fast flushing birds going in various directions and excited hunters swinging shotguns account for a lot of injuries to dogs and people.I do a lot of bird hunting and am very careful about who I hunt with.
Muzzle control is always the ultimate answer to gun safety. Mt father was an NRA shooting and safety instructor. If he ever saw one of us boys handling a gun unsafely, even swinging the muzzle of an 'unloaded' gun across someone he would take the gun away from us and lock it up for 30 days. no excuses accepted. I learned early.
Despite that early training, I had an incident some years ago while hunting quail in the high sage brush of south central Washington. Dog on point, I approached for the flush, not seeing my partner relocate froward and behind some brush ahead of me. Birds flushed, I fired as the birds went out over the top of the brush and peppered the scalp of my friend who was unseen in the line of fire. It was my fault for not knowing exactly where he was when I fired - thought that he was to my right while I approached the point. He knew the dog was on point and I never understood why he moved down the gully behind the brush in front of me. This spooked the hell out of me and re-doubled my concern for safety habits when hunting.
Murphy's Law is always in force.