Carlos Tevez provoked Joey Barton, and Barton fell for it hook, line and sinker. Pic Andy Hooper.
At the time, HKRef suggested that Tevez must have done something to provoke Barton to elbow him. The FA did not bother taking retrospective action on Carlos Tevez and therefore sent out the message that it is uninterested in seeking real justice in the game.
IMHO, Barton is a dedicated, talented and committed player. His weakness is his temperament, which many players recognize and therefore exploit. This is because Barton has gained a bad boy reputation due to the consequences stemming from his uncontrollable temperament.
Referees can learn a lot about officiating effectively from this kind of knowledge about players.