Continuity mistake: When Jack McCallister climbs into the helicopter and closes the door, his jacket was unzipped. A split second later in the next shot when he salutes Dick and the helicopter takes off, his jacket is zipped up, his seat harness is fastened, and he is wearing hearing protection. One might argue that he zipped up and buckled up between shots that we didn't see, but there was no break in the audio track between the two shots.
Continuity mistake: In the scene where Dick, Jane, and Billy are eating dinner on the floor near the fireplace surrounded by candles, you can see Billy jumped up and nearly take a step on a candle, tipping it over. Jane is pointing her arm at the fact the candle is tipped over near the foot of Billy but in the next shot her arm is relaxed as the power comes on.