I think we've found the issue. I wear cargo pants and cargo shorts almost exclusively, and have paired down my EDC items considerably. Main light is usually an 18650 or 21700 powered LED model, clip-carried in my left-front pocket; bezel-down. Only other thing in there is my leather slim-line I.D. and credit card case. Literally nothing else. Back-up light is always some sort of 2AAA LED penlight. Clip-carried, bezel-down in my back right pocket. Only other thing in there is my even slimmer leather wallet. Last light is a small keychain model on my main key-ring. Carried dangling from a belt clip.I have had several of my lights turn on in my pocket, holsters and in my vehicle. Mostly I would like to think its because something came into contact with the switch or it was able to twist on due to something moving. I tend to be on the move a lot with full pockets. I found this with all brands of lights, pelican, surefire, acebeam, nitecore, maglite ect. I did have one Acebeam M10 that would turn on and cycle through the brightness levels with the slightest bump. My 25 lbs beagle walking on the floor while the light was sitting on the coffee table was able to turn it on.
Last accidental activation I had was a brand new (back then) Fenix P3D. Back when I carried quite a bit more stuff in my very non-cargo, black pants. That was about 25 years ago! Nearly burned my crotch back then.