My reasoning is that keepers need a continued run of games to build up confidence. Mannone had kept two away clean sheets and from all reports done nothing wrong. I just think it would have been good to give him an extended run until it appeared he maybe wasn't up to standard. He played in I think 24 consecutive games at Hull last year where he also equaled their club record for most clean sheets in a row. Seems like that spell has really improved him.
I was more annoyed at the goal Szcz gave away against Southampton. It looked like a regulation catch.