Wrong.
The tendency for it to flip on its back is due to the undercarriage being anchored directly into the main spar so a hard landing rips one wing off. The situations you describe are probably true but they account for the hard landings, the subsequent roll overs are due to one wing falling off due to the hard landing.
Look at the BA777, bits of u/c everywhere including up through the wing but both wings are still firmly attached to the a/c. Now look at all the MD-11 roll overs, you'll find one wing a long way from the rest of the wreckage in all cases.