I could be mistaken but I believe he reported the security issue through our regular support channel which is why it took three days to see (instead of our security channel). From the time I saw it, I fixed it with the patch going live within an hour or two.
When I DID see it, tried it myself with a quick shell script that that curled and backgrounded the same request a bunch of times, I just kind of chuckled. It was a good bug. Josip is top notch.