Other mistake: As the Military vehicle jumps off the end of the pier, the engine is heard running at the highest RPMs. But there is no engine to be seen in two shots.
Continuity mistake: As Murdock stands on the deck to dive in the water, he has two bottles of pressurized air on his back. The next shot shows him under water, with only one bottle on the back. The rest of the scene shows him once again with two bottles of air. (00:34:00)
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."