Well, if you care to see it that way. But books are a different medium from film; GL has said that books aren't his thing, he does not enjoy writing them nor does he think he is any good at writing them, and so fair play to him if he wants to stick to film.
A book, even an adaptation, is very much a personal statement from the writer, so certainly from where I look at it that is NOT GLs work; it has none of his feel, it has ADFs instead.
This is not a phenonenon unique to a change in medium. Compare the two film version of 'The Thin Red Line' to each other; same story but clearly very different, and all down to the different writers (and to take us back to square one, compare BOTH versions to the book...)
RC- yeah, you are right. Of course, it was difficult for the book to be based on the film as the book came out first. If any of the novels are going to be rejected from the canon it is that one, and this can be seen in all sorts of little differences in it. Still, the basic rule still applies; it is right unless the film contradicts it.