Considered that, but I've wiped, scratched, and put light pressure on the spot with no visible change. Not sure how it could have been damaged in one pixel-sized spot without affecting the surface or any surrounding pixels.
Sure, I also don't know how this damage could have happened. But, I do know that much, much larger structures sometimes buckle and break for no immediately-obvious reason. I don't see why the same wouldn't be true for extremely tiny ones.
