Let me guess... this thread will be full of infallible people who never make mistakes and will never have anything go wrong, ever.
Yup. I wonder how I knew that.
The one group of people that I'll never go shooting with are the people that think they're "above" mistakes. They're the most dangerous of all.
I haven't had an AD or ND YET. However, we're only human. So, we try to formate SYSTEMS to decrease or eliminate risk. Cooper's 4 laws are such a system. And they work, if followed ALWAYS. ALWAYS. ALWAYS.
If something should become lodged within the holster creating an AD risk, then law number 2 will save your keester.
I've never had an AD, but then I'm perfectly aware that it could happen if I don't stay vigilant.
At a weekly pin shoot, our senior RSO (Range Safety Officer) didn't check the chamber on his Ruger Mk2, and discharged it while putting it in the case, which was a tool box. Of course, he DID follow most of the safety rules, putting it away at the firing line, with the muzzle pointed down-range. Still, it scared the crap out of us. And at our annual Pin Match, we began having a special event, the "Ken ***** (name redacted) Memorial Toolbox Shoot!"
It can happen to anyone. I was also at the CO USPSA National match many years ago, and the "winner" of the women DQ'd because neither she nor the RSO actually checked the chamber before releasing the slide and dropping the hammer (on an empty chamber) at the end of her run... She had the winning time and score, but the DQ tossed her.
Mark