Coming to this a bit late :), but I've got a basic question (which I think is similar to Nesov's, but I'm still confused after reading the ensuing exchange). Why would it be that,

The first player would have expected that, and also played D.

If the second player has more computer power (so that the first player cannot simulate it), how can the first player predict what the second player will do? Can the first player reason that since the second player could simulate it, the second player will decide that they're uncorrelated and play D no matter what?

That dependence on computing power seems very odd, though maybe I'm sneaking in expectations from my (very rough) understanding of UDT.