Okay, you are not thinking coherently. I never said being wrong made anyone a liar. I said that when X tells Y that what Y says isn't true, then X is saying that Y is lying. In the original post that Cozmo commented on, the OP was correct and Cozmo said that what the OP said was "not true". So, yes, again...Cozmo said he was lying and therefore called him a liar.