Is it really such a big leap to assume that fictional people in a logic puzzle or riddle are telling the truth? I don't think so. To me, it's very clear that the names of the people are chosen arbitrarily (with first letters corresponding to the first letters of the alphabet) and that the things they are saying are simply a way to convey the logical constraints to the reader. It's very obvious to me that the fictional people, their names, and the fact that they are speaking aren't actually relevant to the logic puzzle.