Revealing mistake: When Hannibal drives the blue car into the sheriff's office trying to get arrested, the wooden jump ramp is visible.
Revealing mistake: When Murdoch is flying, the man sitting next to him is replaced with a dummy in the wide shots.
Answer: Several times, Face would pose as a doctor to get Murdock out of the Mental Hospital. How easy would it have been to convince airport officials that he was a doctor taking a sedated patient on board? Or simply tell them, this man is afraid of flying, so he had to be sedated. They could say, "Believe me, you don't want this man to be awake."