Continuity mistake: At the auction, the night guard who recognizes Eddie from the heist has a gun in his hand. Anna makes him fall and it has disappeared when he hits the ground.
Continuity mistake: Just after Bruce escapes with the Codex, when he is throwing his grappling hook from one building to the next, he is not carrying his backpack with the book in it. It reappears a couple of shots later. (00:52:00)
Continuity mistake: When Bruce is being towed by the ambulance although the sheet starts ripping in the middle, the knot gives out and it becomes totally detached from the ambulance. Some subsequent shots show the ambulance with part of the sheet trailing in and some shots show it with no sheet. (00:31:36)
Audio problem: When Hudson is being dragged behind the ambulance and the Mario brothers are shooting at him, the bullet that punches through the plastic bag causes a "glass-breaking" sound.
Factual error: The opening voiceover says that the Duke of Milan commissioned the statue of the horse in 1481. The statue was actually commissioned in 1473 and, due to the size of the statue, Leonardo's planning wasn't complete until 1490. The project was abandoned a few years later.
Factual error: When the bomb that is stuck to Snickers head explodes, the explosion starts behind him and the bomb remains intact until obscured by the smoke. (01:17:25)
Continuity mistake: Alfred slashes at Bruce horizontally, but the cut that appears on his chest is at a very steep angle. (01:31:30)
Revealing mistake: When Bruce is making a phone call, the glass of the phone booth is normal. Just before he swings the blond thug around into it, a pane is shown that is obviously fake - it is discoloured and not smooth. (00:47:00)
Factual error: The film takes place in 1981 (the film very specifically states that it takes place "EXACTLY 500 years" after the prologue set in 1481), meaning that the several references to the Nintendo Entertainment System don't make sense, since they weren't released until a few years later, in the mid-80's. ('83 in Japan under the name "Famicom" and 1985 in North America to be exact).
Visible crew/equipment: As Bruce Willis and Andi McDowell improbably make their castle-escape aboard the da Vinci glider, a wide, open-air aerial shot looking down shows the model glider pass right through the shadow of the hovering helicopter that is shooting the footage.
Revealing mistake: When Hudson is researching how to steal Da Vinci's book he comes to a staircase. Along the walls are bookcases - if you look properly you can see these are flat, with the book spines just painted on.
Continuity mistake: When Darwin has Tommy at gunpoint in the limo Tommy puts his hand all the way to the wrist through a strap attached to the car. The shot changes and Tommy is instantly grasping the strap with his hand.
Other mistake: When Leonardo lifts up the bar he has just fashioned, you can hear a couple of people in the background say "Gold" where the others are and correctly saying "Oro" (Since the Italian word for gold is Oro).
Factual error: Although there is a lot of uncertainty about the painting, the Mona Lisa was painted sometime between 1505 and 1515. Certainly not as early as 1481. (00:05:00)
