I think that's kind of it. Romo has complete trust in Dez to throw it to him, but not to adjust a route at the line of scrimmage. They were forcing Dez inside by playing outside leverage with the corner, but leaving a safety inside, and dropping the LB to cut off the slant. The biggest problem was that Romo was taking a beating, and he couldn't wait a doubled receiver (Dez and Witten) to work free. Notice how Dez never goes in motion, and Romo never moves him before the snap. I don't think Dez is comfortable yet with adjustments at the line of scrimmage.