Just curious if anyone has ever had a handgun fall out?
I had it happen one time years ago when I thought it was secure and inside my waistband and as I was walking up just a few stairs, felt it slide down the back of my pants leg landing behind my heel. Inside my waistband. Not secure. 
Hear ya.
Heard one poster sharing how he had a box full of used holsters. Now I also personally know why some of mine have been swapped out for different more secure ones.
I find some holsters retain better, some have a screw or two to loosen or tighten, some a leather flap and metal snap button over the top. Guessing the position plays a part, testing, with all types of body movements.
I even found a holster I thought was superb until once when mother natured called me to # 2, but when I dropped my pants down, one can guess the rest of the story.
Made me realize how even some safety tools are tougher than others (quality).
Appreciate the post, we gotta learn this somewhere, here as well.
I surely hope that you didnāt have to resort to carrying ādirtyā. 
Luckily nope, as it happened first and fast (outside my pants instead of inside), did spook me though. 
Yes, not due to the holster but entirely my fault.
Please tell us the type or model of holster, as well as the type of belt. Did the gun-in-holster escape as a unit, or did the gun escape from the holster?
Definitely @deranged doesnāt carry SIG P320ā¦ otherwise this thread wouldnāt be hereā¦ 
But seriouslyā¦ yeah s.h.i.t. can happen everywhere at the least expected moment, so that why I check my gear every night before I put it on the shelf.
I recall myself losing screws (from both - holster and pistolās grip) few years agoā¦ but I learned from my mistakesā¦ 
In holster and it did a 180 as it slid down, landing firmly on the heel of the full mag with a round chambered. I donāt care to share the brand of holster as it was an administrative failure on my part in not confirming that the holster truly was secured.
Nope. No Sig involved. There is a nice divot in that mag base plate though. 