Quite an interesting point of view on 5Live last night.
An ex-player, think it was Steve Claridge, said that when he had been a player, he was not the bravest and so, when tackling stronger and bigger players, he would keep his leg straight to protect himself. He felt that this was what Barnes had done and because Matic managed to get to the ball before him the result was the tackle that we have all seen.
He didn't excuse Barnes, he said that he would have known exactly what he was doing but that it was a tackle made from a touch of fear of Matic rather than "criminal" intent.