It took many days, but finally the whole of the matter has been summarized in a simple statement. And this statement has been true for as long as I've been playing.
When Gree screws up they may, on a case by case basis, award players prizes that they may have obtained but were given a disadvantage through no fault of their own. Similarly, players awarded items legitimately earned will not have said items revoked should it be discovered they received the items in question due to actions or circumstances beyond their control.