That's not what happened. If RMS had actually argued the case objectively, he would have used reported testimony that cleared his friend. Instead he went off on some hypothetical to excuse the bad behavior (which reportedly didn't even happen) of his friend.
It was the wrong forum, the wrong topic, and the wrong argument. It shows a complete and total lack of good judgement. Combined with his history of such a lack of judgement, that is the standard which we should hold people to.