Conservation of detail. The two excuses mentioned can be assigned greater significance on a meta level.
And an apocalyptic prophecy is much like Pascal's Mugger: the centaur may not be in prophecy mode, so fear-of-embarrassment might keep you from telling Dumbledore, but you'd still rather not take the risk.
"I talked to a centaur and he told me x" is hardly embarrassing. She wouldn't even have to claim to believe it, just say "what do you think of this claim based on your superior experience?" And it's obvious Dumbledore would want to know.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapters 91 & 92 . The previous thread has passed 500 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18,19,20.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: