if you don't like somebody's reply to an offtopic/hijacking/flamebait post, the best thing to do is to rate it "overrated", that way it doesn't go into moderation as an offtopic post, because, well, it was on the hijacked topic. That's the beauty of threading, isn't it -- topics can change.
Overrated simply means, relative to its current score, it's not something somebody browsing at what it's currently scored at would expect.
I "think" that's what the offtopic moderator wanted to say. Or they just got confused because my reply showed up underneath another topic such that the only way you can tell it's really a reply to a different topic was that there were double angle-lines that are easy to miss.
Tip 1: Be sure to quote the parts of the comment you're replying to. Quote multiple levels to recap the discussion from the original article to Slashdot's summary through parent comments if you feel it necessary.
Tip 2: If a comment is far enough off topic, and you can't tie it back to the article somehow, put it in your journal. Then, under the original comment, reply "See my journal" without bonus so that it at least shows up in the other user's messages.pl.