Let's be clear; there is a flip side to this. If there is a play at the plate, and PU is (certainly) watching the play develop and makes the call on a bang-bang play ...... Well, if BU thinks he will now come in and call obstruction by the catcher during that play, because any umpire can call obstruction and PU didn't make eye contact, well, someone's not grasping reality.
But, if he saw the runner forced to take a wide turn at third by F5, fine.