There's one thing for which it's genuinely impossible for V to have a counter: the realization that killing Harry is not in his interests. Speaking in Parseltongue, bound by the Vow, Harry is uniquely prepared to make that case -- assuming it's true.
Well, that's the sticking point. Parseltongue and the Vow prove that Harry is honest. They don't prove that he's right, and Voldemort can simply choose to dismiss any of Harry's arguments as insufficient (which isn't that hard, given that the risk of keeping him alive is the end of the world, and any risk incurred by killing him is probably going to be less bad).
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 113.
There is 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.)
IMPORTANT -- From the end of chapter 113: