Originally Posted by AnemicOak
It's not in the public domain in the US (or in most other places). Just a guess, but that's why he bought a copy?
Exactly. The text of the upload even says, "Since Nevil Shute died in 1960, this book is out of copyright only in Canada or other jurisdiction with copyright expiration 50 years after the author's death. This book is courtesy of Project Gutenberg, Canada."