The evidence is the quoted prose, which is in the style of Pynchon. If the rest of the book maintains that perspective and entertains me in the manner I expect

The evidence is the quoted prose, which is in the style of Pynchon. If the rest of the book maintains that perspective and entertains me in the manner I expect from Pynchon (as apparently it did the reviewer), then I'll be happy to have read the book regardless of who the "real" author is. I read little fiction but I read whatever Pynchon produces, because, since high school, I've always enjoyed his work. That is what the name "Pynchon" means to me: a certain manner of story telling which illuminates the distant (or recent) past through idiosyncratic distortions and personalities. Unless the reviewer has a sharply different experience of Pynchon's style than mine, I will be happy reading this book.