The above does make the case for a DA/SA, LEM, DAK, DAO type trigger. That's what I wish many of my fellow officers carried.... for everyone's safety.
I'm going to hypothesize that it's simply just not addressed most of the time, rather than being delineated in policy.
We are taught to use WMLs to search, albeit in scenarios with a very different context/who what where when why. With that said, there's nothing wrong with using a WML to search for a target that you think is likely to harm you when find them...but there's definitely a problem with using your trigger finger to activate the light as a matter of regular habit, and using your weapon to point at things in weird angles as if it's a regular flashlight, instead of keeping it in a defensible ready position pointed in a safe direction and using splash to light an area.
"Are you ready? Okay. Let's roll."- Last words of Todd Beamer
In 2002 I was running through a backyard following my shift sergeant. I had my pistol in my hand, with my finger off the trigger and firmly along the frame when I slid in a pile of dog shit and fell down. I made no attempt to break my fall, instead choosing to control the muzzle of the gun, but I still distinctly remember it crossing the back of his head.
My agency was pretty hard-core about finger trigger discipline. Violations in training (even with a blue gun) but especially on the street, could lead to documentation, counseling, re-training and eventually termination.
I'm glad that officer didn't get shot in the back of the head.
I was into 10mm Auto before it sold out and went mainstream, but these days I'm here for the revolver and epidemiology information.
Shootout between FBI agent and Crip gang member in Brooklyn:
https://nypost.com/2019/01/15/video-...and-fbi-agent/