I see that you don't understand the concept of sarcasm. As perhaps one of the most sarcastic posters on RF, I know that sarcasm does not rely on lies to make poisoned barbs. Sarcasm
uses the truth to get its point across. With sarcasm, in its purest form, what is said is not what is meant, and relies on the inherent understanding of the listener/reader to detect the irony - hence humor.
In person even, sarcasm isn't so easy to detect, as one has to know the person making the comment BECAUSE they sound like they are merely stating what they believe to be the truth. Often the voice used or the intonation is the only clue that something is completely sarcastic. Trust the king of sarcasm on RF.
For example, if you hear me sounding like Kermit the Frog with a Pakistani accent you can be almost certain that whatever I am saying is meant sarcastically.