"But if you took the book, placed it facedown on a Xerox machine, copied a single page, and distributed to someone else you would be."

Only if you don't put a bibliography entry with it... if you did that then it is protected under fair use statutes. If you were to copy the entire thing and give it to someone else then you would be infringing the copyright... That is how handouts in schools are perfectly legal... as long as it is not the entire work, and the source, and original author are properly cited, and you do not charge money for it when you distribute it there is no copyright infringment.

And technically yes... plagerism is copyright infringement, theft of ip, and what ever else the various industries can come up with.