Getting no results from over doesn't mean there haven't been any items with that many points (though in fact there haven't been any with 9000 points). Over doesn't pull stuff off disk. It just applies a stricter filter to the pool of recent stories from which the frontpage is generated.

I assume swah wasn't expecting any results, it is most likely a reference to http://knowyourmeme.com/memes/its-over-9000 .

Finally, a hackernews I can keep up with.