When Major Marco is in the library investigating the Manchurian Global corporation's doings, as the camera finds him, it shows that he's wearing headphones in the camera's recordings but after that we see that he's actually not wearing them and he's shown putting them on a couple seconds after to listen to the doctor on the computer.
The place where they drill Raymond Shaw's skull is far removed from where the MRI tracking shows they are implanting a new probe.
In the opening shot of Rosie's cousin's apartment, the shower door has swans etched on it. When Ben takes a shower, the swans are gone and the glass is pebbled.
When seeing the red star on the stage through the scope the carpet is already littered with confetti. In the previous shot there is at most one unexplainable piece of confetti to the left, and while there are cut-aways before the scope shot, it is immediately after this that the confetti starts to fall.
In Rosie's cousin's apartment, Bennett Marco sticks his finger through the grating on the vent in the bathroom. From one side, we see him put his finger in the second hole up. From the other side of the vent, his finger goes through the fourth hole up.
Men and women in military uniforms are shown on stage at the convention. It is against the law for military personnel in uniform to participate in partisan political activity.
At the political convention there is a group of people for a range of military services staged around the candidates for the big photo op. This would not be allowed, as the military is forbidden by law from political favoritism.
Apparently, FBI surveillance cameras come complete with big red record lights, and FBI undercover agents are not wired remotely. Instead they carry dictaphones, mark up the tapes clearly with the target's name, then keep them in their handbags, which they leave lying around while they sleep.
In the opening scene where the "Lost Patrol" is ambushed, Captain Marco is shown driving the truck while Sergeant Shaw is riding in the passenger seat. This is highly unusual in Army doctrine, as the senior most ranking individual will ride as the vehicle commander, sitting in the passenger seat. This is also true as an Officer, generally, will not engage targets on the mounted machine gun.
When Raymond Shaw gives Ben Marco the Medal of Honor in the school, the medal is the one presented to members of the Air Force, Shaw was enlisted in the Army.
On Election Day the news ticker for the cup channel shows "Big-Mart posts $40 trillion sales record in quarter's single largest surge" - almost half the entire world's output. While in real life such a figure is extremely unlikely, the movie describes a different, darker reality, in which $40 trillion may not be as much as in real life, for example due to inflation, caused by years of global security crisis, heavily hinted to throughout the movie.
In the last scene of the movie you hear radio chatter over the aerial beach shot. The audio says "NS 10 milepost 79.81, No defects." While this may sound like military radio traffic, what this actually is is an automated announcement system for a railroad safety system. A track side detector for Norfolk Southern Railroad (i.e. "NS") located at milepost 79.81 has just had a train pass by and no axle bearings were overheating (i.e. No defects). This is the message that the train engineer hears over his VHF locomotive radio after the train passes the detector. This was not appropriate radio traffic for this scene.
The length of Tom Jordan's paddle (it's too short for his height) and the way he paddles the kayak reveals that he's not an experienced kayaker as the movie states.
When Shaw enters his penthouse and gets the phone call from his mom we see the empty jack on the side where a phone cord should be hooked into the wall.
In the opening Gulf War scene when SFC Shaw is telling the men inside the transport that they will be moving out soon, one of the men presses the stop button on a stereo CD player to stop the music playing. The music stops, but it can be clearly seen that the CD was never spinning in the first place.
When Marco boards the Amtrak train from DC, the conductor announces the station stops in the incorrect order: Baltimore, Philadelphia, Wilmington, New York. Wilmington comes before Philadelphia.
When Ben Marco wakes up in the park after the tests at his friend's laboratory, he goes back and finds the lab empty. If the FBI closed it down, it was worth mentioning, yet no one mentions it.
Marco drops the metallic device he dug out from his back into the drain at Eugenie's apartment. He frantically tries to open the mouth of the drain to get it back, then gives up. He forgets that, with the faucet not running when he dropped it, Marco just has to remove the drain trap under the sink, he can recover the device as it would just sink to the bottom of the trap.
A TV interview is said to take place in "Desert Storm, 1992" when in fact Desert Storm was in 1991.
Senator Shaw threatens to see Senator Jordan impeached on the Senate floor. Senators are not impeached.
When Marco removes the implant from his shoulder, he accidentally drops it into the sink, considering it lost forever. However all he has to do to retrieve it is to screw open the odor trap underneath the sink, since it has not been flushed away yet. A soldier should have that basic technical knowledge.
In the election war room, when Shaw's mother is rallying to get her son on the ballot, she stands in front of an electoral map that lists Wyoming as having 8 electoral votes and Colorado with 3. These numbers, if written by a "political expert" would be switched.