I have to say my money's on Frey. Read more here.
What's funny is that Talese defends Frey by saying, "When someone starts out and says, 'I have been an alcoholic. I have lied, I have cheated' ... you do not think this is going to be the New Testament." Then later in the article, she says that "And at the end of it she [Oprah] pulled James aside and said, 'I know it was rough, but it's just business.'" And then she clarified that this was something Frey told her Oprah said, in fact that he says he was told something like this several times. So now she believes him? I don't know that I would. And I do think that while memoir might be shaded (of course it is, to tell a coherent story you have to leave things out or collapse them), Frey crossed the line and just made a lot of stuff up.
Enough about me. What do you think?