OK, not as much as I seemed to imply. You're right to call me on it (will edited parent comment).

I was thinking about the Author's Notes for the last two chapters talking about how readers disregard the obvious interpretation, how sometimes when something's clear enough there isn't a twist waiting to be revealed, etc. For some reason when I wrote the comment above, my brain turned that (plus the confirmation of a Quirrel-Voldemort connection) into "confirmation of a Quirrel plot behind current events". Sorry.