I think he played it all wrong. He was supposed to be a unique housemate, but then just played it how a normal housemate would, basically being all tediously apologetic all the time. Might aswell have just done the twists without an actor.
I think he should have played it up in a slightly arrogant way, pretending he wasn't sorry as he didn't really like them, and really annoyed the other housemates. That would have been funny as only an actor would have the balls to do that.