I distinguish between the decision itself and the decision-making process. If you win, you made the right decision, and if you lose, you made the wrong one, and that is true without reference to which decision made the most sense at the time. The decision-making algorithm's job is to give you the highest chance of making the right decision given your prior knowledge, but any such algorithm is imperfect when applied to a vague future. It's perfectly possible to get the right decision from a bad algorithm or the wrong decision from a good algorithm.
Also, when we're discussing things as vague as the intention of an author who is foreshadowing heavily, there's an immense amount of room for judgement calls and intuition, because it's not like we can actually put concrete values on our probabilities. The measure of a person's judgement of such things is how often they're ultimately right, so if he gets it right then I'd have to say that's evidence that he's doing his guessing well. How else are we supposed to judge a predictor? If he's good then he's allowed to put tight confidence intervals on, and if he's bad then he's not. We'll get some evidence about how good he is on Tuesday.
I agree with the principle, but lottery is a really poor example of this, since it implies ignorance.
EDIT: New discussion thread here.
This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. With two chapters recently the previous thread has very quickly reached 500 comments. The latest chapter as of 17th March 2012 is Ch. 79.
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: one, two, three, four, five, six, seven, eight, nine, ten.
As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.
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: