I don't think it's in the actual translation. I have the first 2 Harry Potter novels as audio books and there was no such inserted passage (though I'm not 100% on that since I'm only about 3 months into my Japanese studies and don't understand all of it). The audio book was done by the same person who translated the book as well. (Not read by that person, but she was the one who took the initiative to get it made. Audio books aren't really a thing in Japan and she's been trying to start the genre. I don't know if she's been having success, though I don't think so. I'd love to have the other HP novels as audio books, however).
It's more likely that the uploader inserted some stuff.
Anyway, about authors not letting translators mess with their work... Well, you go write a novel and when it gets famous to be translated into 100 languages, go check them all for accuracy.
There was some famous author whose was translated into German by one of my professors at university (that or some other professor she knew, I'm hazy on the story details, she just mentioned it as an aside in the lecture, so sorry about that) and the press reviewed the translation very highly. The original author, however, got very angry and said she thought the translation completely destroyed her work.
She (the author) wasn't very good at German, incidentally, and wanted everything in the translation to stay the same as in her native language (I think it was English) - even though German requires completely different stylistic choices. (In English "good style" is writing simple sentences, making yourself easily understood, not using a lot of synonyms for the same thing, things like that. In German, you want to make longer sentences in general, being high-brow almost requires obscuring your meaning, you want to make complex sentences packed with information in a very short space instead of using lots of space to explain something in an easy to understand fashion and you try to never repeat the same word if at all possible and use a synonym instead)
So yeah, author's influences on translated works are iffy at the best of times.
Last edited by Zlarp (January 23, 5:15 am)