Somehow this troll succeeded in injuring a student, without alarm from the wards until the point of her death.
So someone tricked those wards, wards that were apparently working when Draco Malfoy was attacked. (Someone tricked them before, but that was by killing him so slowly the wards didn't notice, not by disabling them so no one noticed a student was in mortal peril.)
I wouldn't infer from this that the culprit was necessarily different, since after all in the case of the attack on Draco, the intent was to frame Hermione, and thus the methods used should not have involved anything Hermione herself was not capable of.
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 chapter 93. The previous thread has passed 300 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: