Just had a bad mistake happen. I was going to shoot my G27 at the range so I grabbed a new (ie, untested!) IWB holster for my G23. I have proven holsters but this one was similar to a famous brand and handy at the time. Slipped it on and seemed fine.
While I was out and about I loosened my gun belt a tad for the long car ride, and later when I bent over out plops my G23!!! Fortunately it was in a remote area of a parking lot and I was able to grab it quickly and tuck it back into place. I immediately went to the trunk and ditched the pistol into an ammo box and removed the holster.
Turns out the design of the holster only has kydex on one side and the flexible leather shield on the other side. It holds the pistol if your belt is cinched tight but any slack and the holster no longer grips the pistol!!
Lesson: never ever ever wear CCW gear that I have not worn and practiced with for some time in private. I shudder to think what the scenario would have been in a crowded grocery aisle or such.