"Professor Quirrell had already deduced my possession of an invisibility cloak," Harry said. "And knowing him, he has probably guessed that it is a Deathly Hallow. But in this case, Headmaster, it so happens that Professor Quirrell was under one of those face-concealing white robes."
Edit in response to your edit: You lost me.
To clarify when I said 'actually . . . .' i meant to disprove that assertion not support it.
The example you gave was not an instance of Harry's Cloak being detected or not-detected, so it doesn't prove anything one way or another.
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: