Continuity mistake: McQueen and Brynner take a hearse up the hill to deliver a coffin to the graveyard. When they go back down the hill, you can see a plume fall off one of the horses' heads, but in the next shot, the plume is back on. (00:16:05)
Continuity mistake: In an early scene Travis and Dickenson are in Travis's office. Travis goes to the mantel, gets a cigar and pours himself a glass of sherry. In a later scene, when Travis meets Crockett in the cantina he refuses a drink from Crockett claiming he doesn't drink, ever.
Continuity mistake: The Morlocks aren't affected by the light from metal in fusion in their foundry but they recoil from the light of a match.
Continuity mistake: When the men find the tracks of the dinosaur, the indent is flat and rounded, but when Frosty the poodle finds the dinosaur that made the tracks, its feet are skrawny and have pointy claws, which don't show up in the tracks.
Continuity mistake: Just before Crassus has Spartacus crucified,he tells him the fate of his wife and son. A camera closeup shows a change in Kirk Douglas's hairstyle.
Continuity mistake: As the cabin boy is cutting him loose, David Balfour's bruised cheek and black eye switch from the left side of his face to the right when one shot is reversed. (00:28:00)