haha, you've never seen any? It's pretty classic HN. If someone thinks a comment is false the reply will look something like: "No. What you really meant to say is..." and often times the "No." will be its own paragraph.

Not a lot, but yeah I guess I've seen it. A bit harsh but I don't remember enough specific instances to say whether it's typically warranted or not

(The nerd joke btw is that both of my replies so far started with "No", since you didn't specify whitespace after the two characters o:) )