That is pretty much what I think too. Romo may or may not be the problem with the down-field shots but is he instructed to keep them short? Is he on a leash? Is he only allowed to audible into certain plays? or is Romo simply gun-shy now?
We may never know the real answers so it is all opinions from us. I think Garrett and Callahan are playing a safe offense and not allowing any deviation thus hand-cuffing Romo in the process. He may have more say in pre-game plans but I don't think he has the authority to implement his own thoughts, it has to come from that playbook and scheme, which is definitely lacking.
If the offense continues struggling until seasons end, Callahan will be the fall-guy, question is.....does Garrett go down with the ship or is he the first to jump into the lifeboat and paddle off?