We only have data on reported and witnessed ND's. What we know about and what people tell us about when no one else is looking may not jive.
Most that I'm aware of involve unholstering. We've had an officer here ND a suspect, outside of the square range there certainly is a human risk to it.
The second most common place is during or after training, and you have officers with hot guns that are trying to demo or practice things that should be done with an unloaded pistol. People have been killed because this, particularly in FOF training.
Whether you think you can or you can't, you're probably right.
Coming from a military side of things, the overwhelming majority of our ND's are in clearing barrels - specifically, clearing barrels that don't really need to be there like the ones outside Dining Facilities (DFACs) etc. If I were in charge, clearing barrels would be at ranges and arms rooms exclusively as the absolutely unnecessary admin loading and unloading of weapons just elevates risk, especially when the weapon would otherwise stay in a secure holster.
Officers O4+/CW3+ with M9's tend to be the most common culprit (2/3 times I'd say) with PVT snuffy and the odd dipshit E6 with an M4 making up the other 1/3.
The lesson learned there is to minimize admin loading/unloading of duty weapons. Especially with something like a handgun that can be safely left the hell alone in a proper duty holster.
^^^^My experience as well. Folks get so used to it they don't think about what they're doing, and "drop magazine, retract slide/charging handle, pull trigger" becomes "retract slide/charging handle, drop magazine, pull trigger" with the predictable result.
For LSP, my memory was substantially more from failing to drop the mag before cycling the slide with pistols. With shotguns, unloading by racking.
And dicking with guns they knew were unloaded and didn’t check.......
It bothers me somewhat less when it's after unload & show clear. The times it really tweaks me out are when people go too fast on make ready, don't look, and end up pointing the muzzle of the gun right into their own hip joint and/or ass cheek, sometimes repeatedly, before it finds its way into the holster.
While the Front Sight data has more people shooting themselves drawing than holstering, it is possible they would also have eventually shot themselves holstering but didn’t get that far.
Likes pretty much everything in every caliber.