you are screwed vs. I screwed-up

P told A this morning that he was 'screwed'. C told P not to use such foul language and N said that Obama had said that he "screwed up". Well, my first point was that even the smartest and best educated people sometimes lost their temper and used foul language. And, second, that there was a difference between saying that "I screwed up" and that "you are screwed". The latter being more offensive language because it was directed at someone else - while the former was directed at oneself. Not sure if I believe this, though ;-). It does seem like one is given more leeway when being self-critical than when criticizing others. Right?