Adso and cutscenes

I started playing the game recently (just completed the Crimson Fort) and i'm curious whether there is a particular reason for why Adso appears to be missing in some cutscenes? He gives an explanation for Glinda's house, that Aran doesn't let him enter, but then at the exit from the Crimson Fort he takes notes, then completely disappears for the duration of the exiting cutscene, and after it's over he and Aran speak as if Adso was there the entire time. Then he's gone for the next cutscene as well.

It just looks weird to me. Is it simply because he can be sent back to camp?