When is it okay to lie in non fiction?

In group discussion, I struggled with whether it was okay for a piece of literature to be labled non-fiction when the author purposefully lied in it. To me, that would  automatically make it fiction, but I failed to remember that this is a creative non-fiction class. Creative non-fiction is a gray genre, somewhere in between fiction and non-fiction. There is an expectation in it that people are stretching the truth and adding things in to make the material less dry for the readers. Since that expectation is included in the definition of the genre, it makes it okay for the authors to take creative liscense. Many people don't know what creative non-fiction is though. They don't know that writings like memiores, by definition of their genre, are not going to be a 100% accurate portrayal of the truth. Their ignorance brings about the news stories of readers who feel betrayed that the author made things up.