For what it's worth (and remember you have to consider the source) yesterday on Chicago Tribune Live! Kaplan was saying that he was being told that Robin was questioning A.J. last year on his pitch selection and why he was calling certain things at certain times.
He then went on to talk about how catchers who have some defensive issues want to call nothing but fastballs.
Bob Foltman then mentioned that was the reason Olivo was shipped out, that all he wanted was fastballs to have a better chance to throw out basestealers.
Again I have no idea how accurate this is, but if it is, that could explain some things.