Craig, I really don't think this is degraded gluten. Bill uses a bread machine, so it's difficult to ascertain how much mixing he's doing, but Chau gets this spider web effect as well, and I know, for a fact, that he doesn't overmix.
It's also definitely not overfermentation either, as Bouncer is very strong flour (14%) and overnight cold fermentation is just a drop in the bucket for a dough with this kind of strength.
I firmly believe that for every medium high to high gluten bromated flour, you can add the perfect amount of water, knead it for the perfect amount of time, ferment it for the perfect time at the perfect temp and bake it the perfect amount of time and this kind of extreme/holy grail oven spring can be achieved. It's a perfect storm that, for Bill, involved some luck, but, for Chau, because he does it more frequently involves less luck, although he does have the added benefit of elevation.
What's most fascinating to me, personally, is that a few steps Bill took seemed to counter theories on what I previously believed to be responsible for ideal oven spring. For instance, I believe he was at a 5 minute bake at the time of that photo. I still believe you can't achieve that kind of webbing at bake times higher than 5, but at the time of that photo, I was pretty sure it couldn't be done above 4.
I also seem to have different results using cold dough. I know Tom's a fan of slightly chilled dough, and, in theory, colder dough should allow for more dissolved CO2, but I've haven't seen dramatically higher oven spring with my slightly chilled and/or cold dough experiments.
I was also a huge proponent of high-ish hydration for oven spring. I don't know the exact specs for Bouncer, but, at 63% hydration (or possibly even 60%), he's most like a point or two below the absorption value. I'm starting to experiment more with sub absorption value hydration now, and, so far, it's been a bit encouraging, but I don't think this, by itself is the silver bullet for webbing.
The one aspect that does seem to support my theories is bromate. Both Chau and Bill are achieving this webbing with a bromated flour, which I definitely feel is a player.
As I said, I don't think anything, by itself, is the silver bullet. It's a combination of factors, and everything's got to be dialed in perfectly.