Thank you, I'm glad he's in character! Honestly I think they really are lies he told himself, not mistakes - or, well, mistakes only in the sense that it usually is a mistake to lie to yourself. Even siding with Azula is a lie in the sense that Zuko has said before Azula always lies, and here he seems to be telling himself Azula's not lying this time. (In fact, I always thought Zuko got really lucky that Azula actually upheld her end of things and reported to Ozai such that Zuko got his banishment rescinded.)