Atkinson failed to deliver consistency in similar incidents, the basic requirement for match officials.
Lucky Luiz: The Chelsea defender should have been shown a second yellow card for this foul on Rooney
In the first half, Manchester United were denied a penalty when John Terry handled a shot from distance. Although his hands were by his side, the ball travelled a long way and Terry ensured that the ball did not pass - a clear offence. Nothing was given.
However, when Yury Zhirkov took the opportunity to go over Chris Smalling's outstretched leg, Atkinson had no hesitation in awarding the home team a spot kick. It was soft, but just about the correct call.
Venting his anger: Rooney confronts Atkinson after the final whistle
An even clearer example came when David Luiz deliberately tripped Wayne Rooney off the ball - a clear cautionable offence.
As he had already been cautioned, Luiz should have been dismissed. Nemanja Vidic was not afforded such tolerance later in the game.
Source: Daily Mail