Just listened to this - I was a bit surprised how confident one of them was that Penguin would not be affected by this scandal, and that the Walker/Wynns would be the only ones to experience "reputational damage". Penguin might well continue merrily spinning money out of the books, but I would suggest that they have also suffered reputational damage.
It just seems a bit easy for publishers to say 'well the author signed a contract, how were we to know?' and wash their hands of any responsibility.
If you had been the editor/s looking at this book, wouldn't you have asked a few basic questions about how the couple 'lost their house', and how come they were apparently completely penniless, with nobody to help them, and wouldn't you have asked (tactfully of course) for a few details about Moth's diagnosis? These clarifications need not have been included in the book, but the publisher surely would have wanted to be satisfied that the basic premises of the story were true?