violating the principle of rational discussion

On page 202 of Critical Thinking, Epstein explains about the violation of the principle of rational discussion and how the fallacy connects to those who have disagreements in a ridiculous manner. Often times, the people who violate the principles of rational conversations have a motive in intentionally puzzling and/or deceiving those around him. It’s when one declares a statement that is not in any way or form, accurate, to purposely give misleading information to another person. Often times, one is known to "violate the principle of rational discussion" when the premise of his argument is extraneous to the concluding statement and/or his case can easily be interpreted as false and inaccurate. The other day, I heard someone talking on her phone with a friend. She said, “Don’t use Princeton Review. I studied off of it and still got a bad score on my SATs. It's bad and doesn’t help at all.” That’s an example of the violation of the principle of a conversation that is rational. The girl was mocking Princeton Review, saying it’s no good, when in reality, there may be other reasons as to why she did not do so well. Because she ridiculed Princeton Review to persuade her friend and make her argument convincing, she has just dishonored the standard of a rational discussion.