its still odd behaviour.. look at any similar post (in terms of age/activity) and you can clearly see that one stands-out as odd. here's one that looks to follow a more typical progression - http://hnrankings.info/5719667/
also from making it near the top [rank 3 / 22:30-22:45] it rapidly fell close to the bottom of the front page [rank 22 / 23:10].. that's a pretty quick decline.
This is behavior I've seen before. A rapid rise, staying high in the rankings for a but, then getting a few flags to take it to the bottom of the front page, or the top of the second page. A few more upvotes to get it back on the front page, normal declining with age and/or upvotes intermingled with the occasional flag, then getting hammered.
It's usually on long, unpleasant and angry exchanges that I see this behavior on, and I'm not at all surprised.
also from making it near the top [rank 3 / 22:30-22:45] it rapidly fell close to the bottom of the front page [rank 22 / 23:10].. that's a pretty quick decline.