Revealing mistake: In the day following the Rider's first ride, Cage shows up at the street that has been burned down the center. A person very close to the beginning of that scene walks on the broken up rocks and it moves as if it were a pad or a sponge. It wasn't a rock moving because the street moves with the rock. It happens a couple of times during that scene.
Deliberate mistake: When Frenzy attacks Sam, the teenager wears straight leg jeans with a narrow leg opening (not boot cut) and thick-soled Nikes, seen in numerous shots, as he kicks at the Decepticon. After the cut to Mikaela (who finds the reciprocating saw), during which Frenzy has already pulled off the bottom of Sam's jeans, Sam continues to kick and scream just before he gets up and runs. Problem is Sam still wears both thick-soled Nikes, neither of which slipped off as Frenzy maniacally pulled the jeans, with narrow leg openings, from his kicking legs/feet. Impossible even in the best of circumstances.Super Grover
Revealing mistake: Underdog's first costume is supposed to be a felted down (the more accurate term would be fulled) wool sweater. When wool is felted the stitches lose clear definition and usually achieve a "felted" look. It is clear that the sweater in the movie has just been switched for another smaller sweater as the stitches are still sharply defined after it has been pulled from the dryer. This is especially clear around the U. No attempt to make the smaller sweater look "felted" was made. This refers to the original costume with the solid white U, not the second costume with the yellow outlined U.
Audio problem: Just as McClane and Farrell are about to leave the Eastern Power Hub, Farrell goes on a long rant and his mouth does not match the words he is saying. [In the unrated version of the film, the rant concurs with Will's mouth movements, but the mistake is valid for the regular version.]Joel Amos Gordon
Continuity mistake: In the opening scene, just after the man is set afire he falls to the ground. Frank shoots him and while firing his weapon jams. A casing is stuck in the ejection port (called a stovepipe when it happens). After the round sticks he continues to pull the trigger and the weapon continues to fire.
Factual error: Firearm issues abound throughout the film. The British detectives (who all seem to be armed, rather than a low proportion of AFO (Authorised Firearms Officers) as in real life) are shown carrying Beretta pistols, even though the Metropolitan Police issue the Glock 17. The SFO (Specialist Firearms Operations) officers are shown carrying MP5 submachineguns, which is accurate, but fitted with cheap toy-shop lasers. Weapons handling is poor throughout, with chickenwing syndrome particularly prevalent. Weapons carriage also appears geared to look "cool" rather than realistic; shoulder holsters - which practically everyone wears in this film - are rarely used for concealed carry in reality.
Continuity mistake: During the complete car-bomb chase sequence towards the end of the film, Michael Clayton's car is shown in one shot without its lights on. All the surrounding shots in the scene have both cars with their lights on. This is also a slightly revealing error because it shows that they actually filmed these sequences during the day using neutral density filters. (01:41:15)