I wasn't arguing that mechanical things could never fail. I was just saying that I personally, and those around me, never had a mechanical issue that led to the discharge of a firearm.
Having worked in manufacturing, engineering, production capacities the last forty years I've certainly seen my share of mechanical failures. Maybe I was too quick on my response regarding AD and ND. I didn't think it through thoroughly and yes, in that context an accidental discharge is surely possible. Thankfully, I've never experienced an issue with a loaded gun.
To Kmitch....I owned a Monkey Wards, Western Field knockoff and it worked flawlessly for the better part of my youth and young adulthood. Wish I still had it...

It was the first gun I was able to buy (with a note from my Pop) at the tender age of 13 or 14... I felt like Daniel Boone walking the half mile home from the mall that day, shotgun slung over the shoulder!