It does make the reply look more brash, though. Good that [s]he made it less inflammatory, but it would have been courteous to add "edit: made the tone a bit nicer" or something.
That all depends on the intention. If the intention is to make my response look more hostile, than I would say it goes against the conduct of HN. They could have replied or added a remark in the edit. The poster could have said "editing, sorry for getting too heated" or something if the intention was to deescalate, but this was a ninja edit.