One more thing, -actually several, but this example will do- one of the biggest and most serious calumnies was believed and pressed by Sam Stone on several occasions and AFAIK he never admitted how wrong he was after me and others pointed at the evidence.
There was never an acknowledgement from Sam of how wrong that was, and never a hint about what was his source then. And about ten years after that, I pointed at his error again when he posted that in a more recent and different thread, to no avail.