Continuity mistake: When Ethan wakes up in the hospital he realises he's handcuffed to the bed. In the closeup of his right hand, the handcuff is around his wrist with its single metal bar facing out and the double bar facing Ethan, but when the nurse moves his gurney the handcuff is around his right wrist the opposite way, with the double bars facing out. Quite impossible for this to occur. (00:31:50)
Continuity mistake: Carly's shoes appear to mysteriously alternate several times between black stiletto heels and black ballet flats in-between shots during the climactic action sequence. This is most noticeable during the collapsing building sequence as well as the scene in which Carly speaks to Megatron.
Continuity mistake: When Conan first fights Remo, Conan places a blood stain on his forehead by pressing his sword to it. Remo then runs off, and Conan gives chase immediately, pausing only to get Tamara on his horse. The stain is still there when Conan mounts his horse. The next time we see them, Conan and Tamara is still chasing Remo, but now Conan's face is completely clean. It is highly unlikely he would pause in pursuit of one of his father's killers to wash his face. (00:47:55)
Visible crew/equipment: During the attack on the town, right after Jake breaks Percy's hand to get out of the cuffs and begins kicking the wagon door we see an exterior shot of two people running and just before one does a flip, film crew is visible on the left. We see at least two people sitting in chairs, one wearing a bluish short sleeve shirt, shorts, and boots, and another in a white shirt wearing a baseball style cap. We also see a blue light coming off their equipment. (00:35:30)
Factual error: When Watson is looking at the spiderweb of clues in Holmes' apartment, he is shown a newspaper article about the bombing and doctor's death. The lower left of the clipping shows a story with title "Soviet Government Money For The General Strike." The movie is set in 1891, and the term Soviet first came into use in 1905 to describe a worker's movement in Russia, but a Soviet Government didn't exist until 1917. (00:16:00)