I wonder if it's worth separating out the track record across working by gut and by communicable-evidence channels? Like, if the last 30 predictions he made, he gave reasoning for 27 of them, and all of those were right but the other 3 were wrong, then that's a bad track record for this sort of thing.

Seems obvious, but it might be over-fitting, especially since 'trust me' cases might be rare.