His reasons for that trust may be good or bad, but that appeal constitutes evidence to him.

Sure it is, but always in the context of evaluating the probability of someone to be a good source. If you later find out that Taleeb sucks, then you would lower the value of Kahneman as an authority (as I did).

"Appeal to authority", used as a fallacy in the original comment, evades this by proposing almost-absolute value or truth, for which you should not doubt: "People like you have no idea what Taleb does, and how wildly successful he has managed to be at what all other feeble intellectuals fail at. He is the 'level above'." or "When Kahneman himself says Taleb changed his views, that's the guy".