Have seen this many times when people don't understand the diff between polishing & grinding. This appears to be a classic case of insufficient engagement of the striker lug with the rearmost area of the cruciform on the trigger bar. It drives me nuts when people hawk this gaming stuff as "ideal for CCW." That's a clue to me it was designed by a range jockey who's never found out he would have no problem getting past even a NY-1 or 8# connector if really under duress.
The other time this POS might disengage is when, with gun at slidelock, a really stuffed mag is slammed home. Especially in the compact models it's possible to provide enough 'upward' movement to get that slide off the slidestop. Makes for very fast reloads; works GREAT on a stock gun (again, sufficient striker lug engagement), unintended consequences with a great gun as modified by the Sevigny-wannabe they're talking about.
I don't care if the owner of that thing starts out with the muzzle downrange. If he's not prepared for what's gonna happen next he is an extreme hazard to others. Anyone who's had the pleasure of a G18
knows that you can't lolligag such a thing.
My standard question to many folks bringing me their "unsafe" or malfunctioning Glock is "so what aftermarket shit have you installed inside?"
Glocks & AK's; I love 'em & they love to run and, like Marlene Dietrich, they like to be left alone.