The ref blew when Nani stayed down, he blew when Ballack stayed down he didn't when Evra did why? Inconsistency and poor refereeing.
I missed the Ballack incident but Nani was seriously injured so Foy was right to stop the game.
Of the 2 incidents I saw; there was nothing wrong with Evra so he played on, Nani was injured and he stopped the game. I can't see too much wrong there.