HN policy to avoid flame wars, AFAIK: the reply button is delayed before it appears for a specific post. seems to be around 4 minutes, at least for the deepness of this conversation.
Oh. OK, Thanks for that. I wonder how I managed to miss that little detail! And hey, bonus point, I just discovered that when people continue to downvote you, it still hits your karma, even if the visible post count stops at -4. Two things I've learned about HN today :)