Well, yeah, if an authority says that the Hubble constant is 68 km/s/Mpc and you interpret that in such a way that if the Hubble constant is 67 km/s/Mpc or 69 km/s/Mpc the authority is wrong, then you'd better assume the authority is wrong -- though that's not a very informative assumption and anyway in the real world authorities often make claims more vague (i.e. whose negation is less vague) than that.
Well, sure, you have a relatively high opinion of authority. But even a vague claim needs the expert to be significantly better than chance to be promoted to your attention.
(And, well, this guy isn't a physicist. He's involved in medicine. There's less likely to be clear-cut experimental proof the expert can simply point out in order to overcome your prior. Instead, you get a huge, enormous pile of famous cases where The Experts Screwed Up.)
Another month has passed and here is a new rationality quotes thread. The usual rules are: