Honestly, I think that bottle variation also plays a huge part in it, and you'd probably be surprised at how much it can matter. I've actually done BOS rounds and had beers which were phenomenal during judging rounds that were just OK when BOS came around, especially in comparison to some of the others. To be fair, though, the 49 was in 23, so it's even harder to say what it was up against in mini-BOS vs the judging round. Ultimately, though, it really depends on the variation between bottles and judges. The entrant in me doesn't believe there's that much variation in my bottles, since I bottle only enough to enter. The judge in me, though, has experiences significant differences,
Just as an example, at a recent comp, we had a couple of beers in BOS which were at opposite ends of the spectrum. There was a blackberry sour that had a significant diacetyl profile in the judging round (obvious pedio) that only had the barest trace of it in the BOS. Also, there was a fruited IPA that was great in the judging that had a harsh bitterness and a trace of cholorophenolics in the BOS. That's why the judge procedure manual specifically spells out that the best judging round score should not win, but that there should always be a mini-BOS when there are multiple flights/judge pairs.