Earlier quoted context omitted.
Google Books case establishes that scanning a copyrighted work is not always illegal; you cannot use that solely to prove the infringement. Regarding "books made available for free": libraries allow to read books for free.
It was never anybody's claim that scanning a copyrighted work is always illegal. This is an easy, straightforward decision to read; I think you'd be better off just reading it.
You can apply most of those arguments to a library lending out (distributing) physical books without authorization and causing same harm to the publisher.