The concept came from old timey hammer guns. You'd press your thumb against the hammer when reholstering in case anything snagged the trigger. Literally same concept for a Glock except 100% applicable to AIWB.
Wow, very cool read, I'd recommend Glock lovers check it out. Thanks for posting that Voodoo. My situation was a little different, though. Mine pulled the trigger on the draw. All I know for sure was that my shirt tail or t-shirt got tangled up, then "Click".
FT
NRA Life Member
Basket full of Deplorables Life Member