Revealing mistake: Dialogue in the episode specifically mentions the A2 and A282 roads near Dartford, Kent - the actual roads used were the A1 Barnet by-pass, Galley Lane and Well End Road. The error is revealed by the sight of a road sign that appears just as the Austin Princess Limousine turns on the the main road - the sign shows that the car is not turning on the the A2/A282 near Dartford, but the A1 at Barnet some 40 miles away.
Continuity mistake: When Nguyen falls of a building, breaking his leg he is taken to the hospital. Laying in a bed adjacent to him is another patient. The next shot is a close up of Nguyen. When the shot goes to a far shot Nguyen is alone in his room, the other patient and his bed is gone. (00:41:10 - 00:41:45)