He was too often like that in 'big' games. He dropped a clanger against Arsenal, something that you simply cannot afford to do against your closest rivals in tight games, he let us down against Chelsea on a number of occasions.
I watched an interview with Micheal Owen recently and early in his career he scored at Old Trafford and then got sent off. It taught him a lesson about playing in big games and he became more focused, more cold the bigger the occasion became.
Some players thrive in big games others don't.
I remember he started getting done at the near post too easily - I was right behind the Kop goal, about row 14, for the Arsenal CL QF, had a really clear view and couldn't believe he got beaten at the near post. The 2012 FA Cup final was poor from him too.
Still loved the loon though and he did speak out against the cowboys