[Update: and now there's a fifth discussion thread, which you should probably use in preference to this one. Later update: and a sixth -- in the discussion section, which is where these threads are living for now on. Also: tag for HP threads in the main section, and tag for HP threads in the discussion section.]
The third discussion thread is above 500 comments now, just like the others, so it's time for a new one. Predecessors: one, two, three. For anyone who's been on Mars and doesn't know what this is about: it's Eliezer's remarkable Harry Potter fanfic.
Spoiler warning and helpful suggestion (copied from those in the earlier threads):
Spoiler Warning: this thread contains unrot13'd spoilers for Harry Potter and the Methods of Rationality up to the current chapter and for the original Harry Potter series. Please continue to use rot13 for spoilers to other works of fiction, or if you have insider knowledge of future chapters of Harry Potter and the Methods of Rationality.
A suggestion: mention at the top of your comment which chapter you're commenting on, or what chapter you're up to, so that people can understand the context of your comment even after more chapters have been posted. This can also help people avoid reading spoilers for a new chapter before they realize that there is a new chapter.
(slaps self on forehead) It just occurred to me that the precognition theory is experimentally distinguishable from the alter-reality theory for Comed-Tea.
If Comed-Tea operates on precognition, then the frequency of potential spit-take inducing events (that is, events absurd enough to cause you to do a spit-take were you drinking something) should be the same for communities that have the stuff and communities that don't... the only difference should be that Comed-Tea containing communities drink the stuff just before they happen.
OTOH if the frequencies aren't the same, then the precognition theory runs into trouble. In that case something does appear to be increasing the likelihood of absurd events.
Of course, a third theory is that drinking Comed-Tea simply makes things seem more spit-take-worthy than they otherwise would be, thereby increasing the perceived frequency of such events... much like the frequency of giggle-inducing events increases after eating a hash brownie.