The title was "A Retiree Discovers an Elusive Math Proof–and Nobody Notices". The last three words were unnecessary, very click-bait, and as the first comment observed not even true. Even "Retiree" is strictly worse and more click-bait than the "retired statistician" that we have here. They're hoping to get some people to click through on the idea that the discoverer is a retired plumber or car salesman. A title that terrible should definitely be edited when posted to HN. Actually this post edited the title perfectly. Next time do that, because something so click-bait as the original will get flagged to oblivion more often than not.
EDIT: It seems I can't edit/delete the post anymore.