I think you’re right and that’s what I figured, which is totally fine. This could entirely just be a perceptual thing, but I’m thinking about the goal here of what the reader is supposed to feel about Kanade in this instance. Is she normal but mysterious, much like the girl you just spoke to? Are you supposed to trust her more than the girl you just spoke to? Are you supposed to feel on an even ground in distrusting the two?
I’ll be less opinionated ignorant once I read your TL and start to QC, but I personally took the scene (in knowing Kanade a bit) that she’s very matter-of-fact but simply aiming to help Otonashi who’s being a bit of a raging bull to grasp the situation, much like how she treats most people who she runs into ie Yusa in Heaven’s Door. Your choice could be totally fine and work perfectly, but from a writing and tone standpoint with her voiced lines and appearance here, she doesn’t strike me as peculiar, simply the situation is odd.
Perhaps to make more sense: I think a major point of this whole scenario is deciding who you want to trust, them both being presented fairly. As such, presenting one side as more or less believable skews the purpose of the reader coming to their own conclusion, and rather pushes them towards one.