Factual error: The movie is set in 1948. When Easy first visits Albright about the job, Albright throws some $20 bills down in front of him. The top bill bears the signature of Treasury Secretary Nicholas F. Brady, which appeared on paper currency from 1988 to 1993.
Other mistake: After Marie and Fritz take off to the Christmas tree in the first scene where they talk to their parents, Fritz is shown pulling toy soldiers off the tree to play with. In the first shot of the tree, Fritz stands back up from the toys he has already taken down and reaches for another one. There is nothing in his hands. The spot he reaches for has nothing in it, but as soon as his hands reach that part, a toy soldier suddenly appears in the spot he touches, without the camera cutting. And then in the next shot he bends down and puts his hands on his toys as if he is placing the toy soldier with the rest, but there is again nothing in his hands.
Factual error: In the opening scene with Doug Masters flying in Russian airspace, he is to be escorted back to American airspace by MiG-23s. But in fact the two planes that show up are F-4 Phantoms. When the "MiG" fires a missile, you see a completely different plane. Best I can tell, that is not a MiG either.
Factual error: In two, maybe three scenes, there are ring-necked pheasants. One is early in the movie as the Jameses ride past a butcher shop where ducks and pheasants are hanging up for sale. One is mid-way in the movie in the scene of the house- or barn-raising and big picnic. The movie supposedly took place in the mid-1870s. Pheasants were not imported to America from China until 1881.
Continuity mistake: When Angus and Yellow reach the lake, Angus's face is tore up pretty bad, but after they cross the lake and go to the building on top of the mountain his face is almost completely free of any injuries.
Revealing mistake: At the cemetery, a reporter nudges a headstone and it moves, revealing it is fake.
Audio problem: On the video version, in the barbecue scene, the band starts playing the slow song. The camera is on Eddie and his daughter and they are dancing. If you look closely, the male singer in the background is shown standing on stage and just holding his guitar and not singing, even though the vocals can be heard. In a later shot, he is actually singing. Still later in the scene, he is shown just standing on stage and not singing.
Factual error: At a very early point in the film, the King says something along the lines of "....and these are your playmates". In the background is a horde of 17th century ladies boating on the Achille Duchenne water parterre at Blenheim Palace. The palace wasn't built until the late 18th century, and the parterre was not designed until 1925.
Visible crew/equipment: When Jeremy impales himself on the silver ritual knife, watch as the "knife" bends under the weight of his body - an obvious rubber prop.
Continuity mistake: When Tommy is buying the right to perform the Parker brothers' material, Tommy asks to see the material that he's just bought. He stands up and turns the chair round so that it's facing away from the table. The shot then changes, and he turns the chair round so that it's facing away from the table again.
Continuity mistake: During the camping trip, when Chevy and JTT are talking about the guys who have come to kill Chevy, JTT's feather changes colors from plain black to black and white.
Factual error: In the movie, Wild Bill has a shootout with the bad guys in the stables. He is holding two colt revolvers, each having the capability of holding six rounds each. However as a safety precaution, only five rounds were loaded in the revolver with the hammer resting on an empty chamber as a safety. Therefore, he could only have ten rounds total from the two colt revolvers. He fired far more than ten rounds without reloading.