In regards to the pulling the cart while the save is being written, even that method is NOT foolproof. It is true that game developers have to DELETE a corrupted save. However, if they did a CYA, then it is possible that they keep for each save slot, 2 slots, primary and backup, and in such a way, that whichever one has the higher revision number is current, and the one with the lower revision number, or the one which is corrupted, is the slot overwritten.

(If I were developing a system of that sort, I would verify not only revision number, but whether a given slot for that revision was not corrupted. (If it was, then I would attempt to overwrite that slot, rather than the known good one. If done right, then it would be effectively impossible to abuse cart pull while writing to clean the slate.))