Not to start a rant about Glocks or other designs without a safety, but the more I read about incidents like this, the more I understand why a 1911 type gun carried Condition 1 is such a good idea.
There are way too many holster designs that have some kind of retention strap, and these can "curl in" and find the trigger guard as you are reholstering. With a Glock type gun, ND can be the result.
With a 1911 with the safety on, you're pressing against a trigger/sear that is blocked by the thumb safety. Eventually you'll figure out why the holster thing isn't working for you, but a ND isn't likely.
Same thing goes for the unfortunate pilot with the lock requirement. Gun probably didn't have a safety, and holstering with the lock ahead of the trigger instead of behind it results in a ND.
Sounds crazy, but if things progress in the "correct direction", with CCW being an accepted fact of life, we may see safe discharge cans (or tubes) in more locations which require administrative handling of firearms. Like courthouses.
There was one of these at a police range where I used to shoot. The protocol was "cold range", so uniformed officers had to show clear before entering the range proper. Part of this was dry firing the weapon into a sand-filled tube. I asked the rangemaster how many times it actually had handled a discharge, and the answer was "Far too many".
So, while bashing LEO's isn't fair, there may also be some truth to the point that they are merely average rather than super-human.