The foreword, or afterword are works unto themselves as they make a conclusive point. They also must carry thier own copyright, apart from the body of the book.
It is not uncommon for a book to have several copyrights attached. The artwork for the cover is separate, for example.
I do not have the book in hand, so I posted the warning about it.
I do not know the fine details of copyright law, so I err towards the safe side.