Phil confesses because he wants to be punished for not realising Ben was suffering, according to Inside Soap. I am surprised they got away with some of the scenes pre-watershed, but Sophie Thompson has been good.
When they showed that programme about how they did the 'drowning' scene, it was obvious that the actor is very different from the character he plays - he was laughing and joking all the time. By the way, what's happened to Steven? Have I missed something?