Factual error: A convoy of open trucks arrive at the camp bringing the latest batch of prisoners, many of whom are carrying rucksacks and tote bags of clothing and other possessions. Where did they come from? Combat servicemen in World War Two did not carry overnight bags with them - a change of clothes or a handy supply of toiletries was the least of their concerns. A prisoner of war arrived in the camp with the clothes he stood up in and nothing else.
Character mistake: On the day Rebecca arrives home, Junior Douglas says that he was "Valedictorian, Class of '95." Earlier, Drago talked of almost killing Running Buffalo "during that trouble back in the '40's," which would have been about 50 years earlier. That would mean Drago and McLintock were fighting Indians when they were babies, or possibly before they were born!
Continuity mistake: When they arrive on the island of Talos, the bronze giant, Hercules and Hylus find the statues atop huge plinths. In close up, they are looking up at the statue of Talos, then in a wide shot they start to walk towards it across bare rocks, then in close up they are back where they were with plants behind them.
Continuity mistake: In the scene where the two men are carrying the coffin with the cross on it down to the crypt, the coffin is being held with the cross pointing towards the last man. But in the next shot the cross is pointing towards the first man, as the coffin has been turned around. Then in the next shot the coffin is in its original position, with the cross pointing towards the last man. There is not enough time for the coffin to rotate this many times between the two men carrying it.