The amazon book page is confusing, it lists him as a co-author. The book's cover says it's just a foreword, so I guess you're right.

Still, not to surrender in this thread completely, letting such type of person to write a foreword for a book is not a very good initial signal in itself - it casts doubt on the main author's judgement with regard to whom she considers an authority in matters of communication (or, in any matter other than producing confusing statements).

I haven't looked too closely, but the author was already dead by the time this edition came out so it's quite possible he had no say in the matter.

That's standard practice for Amazon (the author of the introduction being listed as an author of the book). It's confusing and annoying.