That was a huge FAIL on the part ofthat gun owner. I'll bet the he's set that holster on a belt daily and to not see that crease developing was inexcuseable. However, once the lawsuits start I'll bet you'll never hear him admit it.

This is why I don't like striker fired guns with only a trigger safety. My Springfield XDm has a grip safety in addition to the trigger safety and you can hammer the XDm into a holster and if you don't depress the grip safety it won't fire. Another plus is that in addition to the trigger, the slide is also locked by the grip safety so it can't be pushed too far out of battery by a tight holster. However, I don't carry my XDm, it's basically for HD or range use.

My carry choice is a Sig P239 with the DA/SA trigger. With that one I use the same habit developed with a revolver, that is a thumb on the hammer when holstering, if I feel that hammer starting to move I know I need to stop and see what's snagged the trigger.