This is a continuation of the Ashley Barnes trip of the ref that time. Professional players are paid to know where their feet are. It is not like you or me. Keane know where his feet were and what he was doing.
Correct decision. Player's ankle get raked - that's painful and stops him moving that foot to control the ball. Clear and obvious error in that seen on replay and not by the ref. I'd be upset had it been against us but it would have been correct.