That is true, but not relevant to the point I am trying to make. If P took the first offer, they would end up exactly as well off as if they hadn't received the offer, and if P took the second offer, they would end up better off. The fact that P's beliefs don't correspond with reality does not change this. The reason that P would accept the first offer but not the second is that P believes the universe would be "better" with the cube. P does not think ey will actually be happier (or whatever) accepting offer 1, and if P does think ey will be happier, I think that is an error in moral judgment. The error is in thinking that the box is morally relevant, when it cannot be, since P is the only morally relevant thing in this universe.