It was a red card offence, if O'shea shared your oppinion that Torres wasn't going to get the ball why the hell would he foul him. He denied Torres the opportunity to make it a goal scoring chance.
Should have been sent off, wouldn't have been on the pitch to cross to berbatov for the winner and we would have had a different result.
Howard Webb is possibly the most biased ref i have ever seen and i'm not even forgetting about mike riley in making that statement.