What do you mean? He narrated the whole sequence before the explosion, and fell to his knees at the moment Voldemort supposedly died, which is coincident with the explosion. I don't see a problem, let alone one that would be fixed by shifting the narrative back 20 seconds.
Due to the finite speed of sound, the explosion would have had to occur approximately 20 seconds before they heard it. So if Voldemort's death was coincident with the explosion it would had to have happened about 20 seconds before Harry said it did.
...She'd just about decided that this had to all be a prank in unbelievably poor taste, when a distant but sharp CRACK filled the air. [...] "It worked," Harry Potter gasped aloud, "she got him, he's gone." [...] "I think it's in that direction." Harry Potter pointed in the rough dir
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 116.
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.)