I went and looked at the original post - it's very long, but does actually address Thomas' question:

Or imagine that the combination [to the lock that we're trying to pick] changes every second. In this case, 0-0-0-0, 0-0-0-0 is just as good as the randomized algorithm - no better and no worse. What this shows you is that the supposedly "random" algorithm is "better" [than trying 0-0-0-0 repeatedly] relative to a known regularity of the lock - that the combination is constant on each try. Or to be precise, the reason the random algorithm does predictably better than the stupid one is that the stupid algorithm is "stupid" relative to a known regularity of the lock.

Given the length of the post, I think the most reasonable assumption is that Thomas had forgotten that that particular point had been covered by the time he reached the end of it. I know I had by the time I saw his original question.