Actually, regardless of what sort of film review session you are referring to, I will say:
I think it's always better to get 1st hand info when possible. So, imo, it would be better for the PGC to hear directly from the QB what he likes and doesn't like.
Could the OC and the QBC explain preferences? Sure, but it will be an interpretation of what they thought they heard or of what they wanted to hear. Often, that means context and nuance will be lost in the interpretation. I think that is just a part of human nature, not necessarily anything deliberate.