As a gunsmith perhaps you could speak to that.
To get the thread started, I will tell you that when I first got my 700, sometime in the 1960’s, I ignored the instructions and put some sort of graphite oil combination on the bolt.
Cold weather came along and I had several hangs where the trigger was pulled and the gun did not fire. All with Remington out of the box cartridges.
That is a very awkward tense deal. You are holding a gun that you know is going to fire but you have no idea when. Only option is to point it at the ground and wait.
So I cleaned it up and it has never malfunctioned to this day.
I suspect that most of the incidents are dirty guns or guns to which improper lubricants have been applied.
The idiot who shot himself would more than likely to have not properly cared for his gun. If he didn't know better than to allow a hang to point at himself or anyone or anything else other than the ground, he certainly would not have known how to maintain it.
My understanding is that most long guns used by police departments do not have a specific person assigned to the care and maintenance of that gun.
So when needed, someone just grabs them off the rack.
Of course that will vary from department to department.
I have a double set, double throw target trigger on one of my rifles and I love it. The main trigger is set for 5 lbs., but when the second trigger is set the main trigger pulls at about .4 lbs., possibley less.
I would love to put that trigger on all my rifles.