My Camera adapter has a flared end going into the scope. With a focuser using friction screws, the screws once in would physically prevent the camera adapter from slipping out. The only way for that to happen is if the screws broke.
With a focuser using compress ring, the adapter is held in by friction, and due to the flair, has less surface area than usual. Camera adapter can slip out if static friction is insufficient.
My old scope used friction screws, new scope uses compression ring. You know what's coming next...
Yep, it slipped out and fell in the middle of slewing
Fell about 1.2 m onto hard tiles and bounced... seems ok though...