There is simply no way anyone can say the 1st stamp was deliberate, there is nothing at all to suggest he done it on purpose, Costa is like a dog playing fetch, he has his eyes glued on the ball, and looks desperate to get it, imo it was not deliberate, and without question no one can say he meant to do it and back it up with any facts, because no one other then Costa knows what was going through his mind as for the 2nd one that clearly was accidental, so i have no worries about that one so i just hope Oliver tells the FA that he simply cant say whether Costa meant it or not, so therefore he would have given him a yellow card or not punished him at all, because imo that is what any sane person would say.