Here is video of Evra going down after contact with Suarez. Before you watch it, here are the FA's words:
In the 58th minute of the game, Mr Suarez fouled Mr Evra between the edge of the Manchester United penalty area and the corner flag at the Kop end. It seemed to us to be a deliberate foul, and the referee awarded a free kick. The foul was committed by Mr Suarez kicking Mr Evra on his right knee. Mr Evra explained that he had previously had a bad problem in that knee. He remained on the ground receiving medical treatment for about one minute after the tackle... (Culture, English Premier League, Liverpool FC, Luis Suarez, Manchester United, Other Leagues, Patrice Evra)