Is it just me who thought he was absolutely fine? It was Matic's suicidal pass which caused the situation and even then it was a very harsh decision to award the penalty considering he was moving his arm away and it hit his shoulder. Even Peter Walton said it was harsh, and if you've ever watched a game on BT Sport, you know how protective he is of referees and their mistakes.
After that aberration he settled down very nicely and did what was required of him. It was very easy, truth be told, but what was required of him, he did it well.