What you *should* have done is do for her whatever you agreed to do, namely type her paper for her. You could have stopped at that section, or waited til afterwards, to discuss its validity with her. Wouldn't it be better to convince someone of your views than to just tell others she believes it? At the very least you probably could have gotten her to add in "if consumed in the same fashion as a cigarette", because even you said "it can deposit more tar". Well, at least she won't be asking you to "help" with her course work in the future .