Continuity mistake: In the part when the two American officers are looking around in Anchorage, USA, and come across the dead woman at the News Studios you can clearly see her blink 2 or 3 times as the camera pans out.
Continuity mistake: During the long shots in final scene as the submarine is leaving, the wind is so strong that the flag flies straight out behind the conning tower. During the close-ups of the crew, their shirts and hats show no wind at all.
Continuity mistake: Two scenes in the movie show a closeup of the tower on the submarine with a plexiglass shield in front of the actors. Both times you can make out the reflection of trees as the camera moves.