One could use his flip flop to invalidate his new position. But one of those two positions is true. And if they guy who spent the most energy on position 1 changes his mind, that is worth paying attention to. His second position is likely a more informed, and true, position.
I don’t see why one of these two positions must be true. And just because he spent a lot of energy trying to convince others of his obsession doesn’t really convince me he has greater insight the future or how the complex consequences unfold.
That's totally true, I have no issues with a changing opinion over time. The problem is expressing both opinions with 100% certainty and not updating priors to consider that your new position could also be completely wrong.
