Borrowing a line or even a paragraph is lazy. Offering to BUY A PAPER is criminal. Each school makes its students aware of what the penalties are for plagiarism, so she has no grounds to complain about whatever Lewis deigns to smack her with. If you can't do the time, don't do the crime. She deserves whatever she gets.
I would not have cashed the check. I don't know if Nate did, but I wouldn't. I'm all for fucking with stupid people, but I would feel dirty taking money from them.