Belated reply here, but the answer may be interesting to some people: when comments breaking the site guidelines stay live and/or unflagged, it gives the impression that it's ok to post that way to HN. Therefore, even if the two of you were both fine with the interaction, it has a negative effect on the community.
One could put it this way: each post to HN doesn't just say whatever its content says; it also contains a metamessage about what kind of place this is. Since we care very much about what kind of place HN is, and will become, we have to care about that.
(Incidentally, flagged responses aren't removed - they remain visible to anyone who turns the 'showdead' setting on in their profile. You're welcome to turn it on, but if you do, please don't forget that you did! https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...)
