Usually, when you see dang replying to someone, he's reminding them of the HN guidelines and very gently and patiently explaining that they're violating said guidelines. The implication I tried to make was that I had violated the guidelines at least once, dang had replied to me and I had agreed with him that I was in the wrong.
I don't disagree with your observation though. I have developed this habit of explicitly saying "I agree" before elaborating to defend against such misinterpretations of intent.