Does your shit ever legit "pop off" the bowl? Lol

I was cleaning the outside of my pipe (it's slightly rough on a small spot but only superficially) and my crackback just came loose? I don't know how else to explain it, I think maybe I was rubbing the rag too fast? I have no idea it just unattached to the bowl. Yes, THE ENTIRE CRACKBACK LOL so it almost fell out of the pipe but I was quick to cover the hole and saved it. It's the first time this happened I think, second at most and with a totally different and new pipe, so its kinda funny has it happened to you guys? Im sure its no big deal its just interesting and im surprised cause if I was pressing the bowl with more strength than needed, I wonder how it didn't crack or break.