I think the cause is that the vocalist has a flunctuating pitch or what you call it, she's going between notes, it'd be very hard to fix with AT, you'd need an outside plugin to fix it properly. It might be possible with the machiniste but thatd nedd a lot of chopping work.
And i know what you mean Untrust, it does seem kinda out of place a times. I tried 'Speeding' it up with the Rass but no luck. Oh and filtering with varying resonance levels to try and 'ring' it into the note, if that makes sense