Was he? He was dropped for the semi final in the EL, even though he was the gk during the campaign, and then we brought back Henderson. We couldn't register him, meaning that we would pay him 4 millions even though he couldn't play, he wanted to leave and we still demanded 10 m euros for him. From his perspective, he had the chance to become the 2nd gk for another PL club, and if he could impress he may have hoped that Everton would offer him a 2 year contract with very decent wages. I find it completely rational that he was annoyed by our handling.