I’m suprised to hear that Police carry their weapons made ready all the time. Can a copper confirm this? When I was in NI in the Army our pistols were loaded but not made ready i.e mag on, not cocked. Before we entered any buildings on a base or police station they were always unloaded i.e mag off,no rounds in chamber.
I’d agree that the unload/make safe is the most likely time for an ND, especially when tired. A colleague of mine once had an ND on camp, I was the first one to get to him after the shot. I was expecting the worst, but when I got to him he was standing up, white as a sheet with his pistol pointing at the ground and a hole in the tarmac literally a centimetre from his toe. He lost a month’s pay for that.