Where I have seen this get dangerously close, has been when an ejector is too long or the OAL is too long and there is not enough clearance for the bullet nose to clear the chamber mouth, it will jam the case head against the ejector and trap the whole cartridge sideways. One of my pistols did it while fitting a longer ejector. No boom, but it did dent the outside edge of the primer.
Cartridge flipping is a bad habit, and we don't allow it at our range, it blocks the RO from being intent on the firearm during unloading, places the shooter in a bad position if I had to grab his shoulders to control him, and last, the Newbie sees Grand Master Bob do it, and then tries it, gets confused, and forgets to drop the mag first and pops an uncontrolled round ( hopefully ) in a safe direction.