Deliberate mistake: As Nancy and her Mum are leaving Rod's funeral, you can see the shot of them leaving the funeral has been sped up. Watch the Volvo "jerk" as it pulls away as the speed is rapidly increased.
Deliberate mistake: Dr. Chandra returns to the Leonov at the end of the film with the device that Dr. Floyd designed to cut HAL's memory circuits. He hands the device back to Dr. Floyd, who tosses it in the air and catches it when it falls back into his hand. One problem - there was no gravity on the ship at the time. (01:44:00)