Romo's explanation of that last INT, where it had nothing to do with the WR being open, but confusion between the WR and QB about what to do with the route when there is no safety, was worth whatever they are paying him this year.

Romo says they have a plan for Cover 1 (seam route) and Cover 2, in route, but not for Cover 0.

It was Cover 0, WR stopped to break off route, Cam threw the seam.