Signs of leglimency can be detected, so if Quirrell is leglimizing Harry, he may be risking getting caught.
The fact that Harry has an occlumency teacher who uses leglimency on him in an instructional setting might serve to disguise other people using leglimency on him though. We don't know what kind of evidence checking for leglimency can provide about recency and whether the mind has been accessed by different people.
However, I doubt that Quirrell has been using leglimency on Harry, because there's a point where you're really just giving the antagonist too great an advantage, and if Quirrell has been accessing the contents of Harry's mind undetected, I would have an incredibly hard time buying the protagonists not being completely fucked (tvtropes link.)
There is some time resolution.
Albus said heavily, "A person who looked like Madam McJorgenson told us that a single Legilimens had lightly touched Miss Granger's mind some months ago. That is from January, Harry, when I communicated with Miss Granger about the matter of a certain Dementor. That was expected; but what I did not expect was the rest of what Sophie found."
Edit: New thread posted here.
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 86. The previous thread has long 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.
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: