I watched the replays a lot (a LOT!) and I really don't think Webb can be blamed for yesterday; where was the 4th official when he needed him? Webb turned towards Balotelli as he was stamping, but he was looking at the ball and then Mario's face; I don't think he would have seen the stamp. And for the Lescott situation he was following play whereas the incident was far off the ball.
I don't think he can be blamed for missing those; that's what the assistant refs are for. And I really think he did well with what he saw (as I referenced before, e.g. Parker's hard but fair tackle on Richards).