Here's the thing though, according to the rules at the time the Callum McManaman and Robert Huth incidents, they couldn't be done by the FA cause the official has seen and acted on it. It isn't a case of the FA being inconsistent, it's the FA upholding it's own rules which were laid out at the start of the season. I guarantee you if neither of those incidents had not been seen by an official they both would have been banned. As it is if the FA had acted on them, against their own rules, it leaves them in a very actionable position by both Wigan and Stoke. The McManaman incident actually forced the FA to change that rule because of the outcry.
Charlie Adam got done because it was a snidy way to hurt someone. Doesn't matter that it looks less painful or wrong that Huth or McManaman, in the opinion of the FA he fell foul of the laws of the game and got punished. Much like Pardew, it doesn't matter if that was a shit headbutt, he headbutted a guy and will get deservedly punished for it.
