I don't know why he contested the charge. Poor advised - was pretty clear cut.
Think a one week ban would have been sufficient. Perhaps harsh on him, as others probably haven't been punished before for similar incidents, but an example needed making to clamp down on it. On the BBC podcast though they said the entry level offence carries a 2 week suspension, and maybe due to previous they couldn't reduce it.
Hopefully this will be of comfort to referees so they know that they can penalise players probably in future and will receive backing. I wonder if the post match assessor told Karl that he shouldn't have been so lenient