Let's not get bogged down in the specific procedure of getting to Oz. My point was that if you truly adapt merely seeing something written somewhere as your standard for evidence, you commit yourself to analyzing and weighing the merits of EVERYTHING you read about EVERYWHERE.

No, you can acknowledge that something is evidence while also believing that it's arbitrarily weak. Let's not confuse the practical question of how strong evidence has to be before it becomes worth the effort to use it ("standard of evidence") with the epistemic question of what things are evidence at all. Something being written down, even in a fairy tale, is evidence for its truth; it's just many orders of magnitude short of the evidential strength necessary for us to consider it likely.