Cup A' Joe - S3-E14
Revealing mistake: After Hannibal gets the two goons in the van and takes off, if you look through the driver's window, you can see the van rocking, but the trees behind them aren't moving as they should.
Cup A' Joe - S3-E14
Revealing mistake: As Hannibal pulls the semi into the loading bay, the dust runs toward the tires from behind rather than away from the front, showing that the shot was run in reverse.
Waste 'Em! - S3-E21
Revealing mistake: As the garbage truck follows Hannibal's van, when the camera has a wide shot of the goons in the garbage truck, you can the background scenery over the driver's left shoulder never moves.
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."