[Hm...this sounds kind of familiar. Akito knew Kaworu for some time and knew he didn't understand emotion. Could it be possible Tieria doesn't either?]
It's probably because logic doesn't work when people who have had issues with each other before have to deal with their dislike of one another. Logic needs to take emotion into account and change depending on what emotions are around those involved. [He hums a little, wondering who those from Tieria's world are. It's obviously not Alle and Setsuna, so it would have to be others he hasn't met...]