I am not a lawyer, but I can surmise this. If the publisher had a leg to stand on and I got asked, in court, if I was aware this was an excerp from a copyrighted work, I would have to answer yes.
To that end, HTC would be in deep doo-doo.
When I do not know the source of material posted, I can plead ignorance. If something is posted which is copyrighted, and someone points it out (including some information showing the copyright, so it can be quickly determined it is) we can deal with it.
As I said, I had read this book, so I knew immediately it was quoted from the book. I was not sure about "fair use" in this instance as it was quoted in its entireity and not just a partial quote from the work.
Nash, if you have a question, ask it. Your opinion is way off the mark. Just FYI.