the question then is, does that quote, placed in context, somehow make the overall post more condescending than it already was?

"They are probably not crazy" strikes me as "damning with faint praise". IMHO, it definitely raises the overall condescension level.

Whatever condescension occurred, it occurred as soon as Wei said that he was right and Aumann et al. were wrong.

No. Peons claim lords are wrong all the time. It is not even impolite, if you are willing to admit your mistake and withdraw your claim reasonably quickly.

Condescension starts when you attempt to "charitably" analyze the source of the error.

Do you agree that if this were true, if the experts got it wrong, then we ought to try to understand how that happened, and not just dismiss them as crazy?

Of course. But if I merely had good reason to believe they were wrong, then my most urgent next step would be to determine whether it were true that they got it wrong. I would begin by communicating with the experts, either privately or through the peer-reviewed literature, so as to get some feedback as to whether they were wrong or I was mistaken. If it does indeed turn out that they were wrong, I would let them take the first shot at explaining the causes of their mistake. I doubt that I would try to analyze the cause of the mistake myself unless I were a trained historian dealing with a mistake at least 50 years old. Or, if I did try (and I probably have), I would hope that someone would point out my presumption.