The publisher has a contract with whomever the owner/possessor/reader of the book is.
What makes you think that a bookstore clerk has any authority to grant customers the right to re-publish the book's author's work? The book's copyright owners (be it the author, the publisher, or whoever it may be) does not delegate such authority to resellers or their employees.
A man goes to a liquor store and tells the clerk he doesn't agree with underage drinking laws and that if that was okay, then he'd still buy the liquor. The clerk rolls his eyes and takes the man's money.
Does the man therefore have the right to serve the liquor to minors?
A man goes to a car dealer and tells the dealer he doesn't agree with speed-limit laws and that if that was okay, then he'd still buy the car. The dealer rolls his eyes and takes the man's money.
Does the man therefore have the right to ignore speed limits while driving that car?
A man goes to a gun shop and tells the dealer he doesn't agree with anti-murder laws and that if that was okay, then he'd still buy the gun. The dealer rolls his eyes and takes the man's money.
Does the man therefore have the right to shoot whoever he pleases with that gun?
