Continuity mistake: During the scene where Ness kills the Italian mobster in the lodge near the border, the moment he shoots him the wooden rail behind has two sticks underneath, half a second later, when the mobster is flying backwards dead, the sticks disappear, and a second afterwards, when he is laying dead, the rail's appearance has nothing to do with the previous two.Sacha
Continuity mistake: The hand written note with the "I'm very proud of you" is different between the two times it's shown, even though it's meant to look like the same paper. The second time the "V" is capitalised, the writing is not slanted, and all the rectangular foldings from before have disappeared.Sacha
Continuity mistake: In the final court case, as Eliot Ness escorts out Nitti, Ness's wife watches them leave and is wearing a brown and cream hat, with a brown jacket. When the case finally resumes and the guilt plea is changed, Ness's wife is again shown, except this time she's wearing a light blue hat with dark blue ribbon, a blue jacket, with a floral green and blue blouse.
Continuity mistake: When Malone takes the Untouchables to the post office on a liquor raid, he gives his shotgun to Stone and uses an axe to break down the door. When he reaches through the door to open it, the view switches to inside the room. Malone comes through the door with his shotgun again. There is no time for him to drop the axe and retrieve his shotgun. (00:35:25)