This is not a court room and whether Ms Corby is guilty or not is irrelevant.
The point is that by denying the ad in it's terminal the company has given the sort of publicity that the publishers could have only wished for.
If they had done nothing the book would have been just one of a numer of books that come out every few weeks and after a while fade into oblivion.
It is decisions like this that really make me wonder about the capability of senior management