The ref in the world cup final never saw Zidanes head butt he saw the replay after the event and rightfully sent him off, when you see Ramires leg do you honestly believe it was only worth of a yellow card?
There have been far worse injuries than that caused by completely legitimate tackles. Like the one that put Liam Rosenior out this season for months. He had no complaints - it happens in a contact spot. It seems Mike Dean just doesn't like the sight of blood. People are going on about this like his leg was hanging off... it was only a nasty looking gash but nothing a few stitches couldn't sort in a couple of minutes, as was proved by his role in the celebrations.