The interior of the aircraft is supposed to be a Boeing 767, but the exterior shots are of an Airbus A320, Boeing 727, Boeing 737, and Boeing 777.
(at around 56 mins) When Lisa stabs Jack in the throat with the pen, she is seen stabbing it in and pulling it back out, yet in the next scene the pen is still in Jack's throat.
When Lisa is being chased through the airport and falls, she gets up and runs right, but in the next shot, you can see that she was supposed to run left to get to the train.
(at around 13 mins) Straw in Lisa's drink at airport bar is there, then gone, then there again.
(At around 1h 10 mins) When Jackson pries open a locked door with a knife in Lisa's house, the tip breaks off, but it is intact in the next shot.
It says in the description that the flight is at 30,000ft. Eastbound flights travel at odd numbers, not even ones: for example, 29,000 31,000 etc. The even altitudes are for westbound flights.
The missile launcher's case seems to be airtight. If it wasn't, the case should be filled with water and would be very hard for two men to lift. But if it was air tight it would have been much more buoyant in the water.
All the vehicles at the airport, including the cab (supposedly in Texas), are missing a front license plate as required in Texas.
The aircraft cabin is that of a 767 (2-3-2 seating), however when they show the cabin door to the jetway it is one that swings open. A 767 door is motorized and slides up above the ceiling panels.
The flight attendant offers blankets, but carries only pillows.
You can see when Jackson is throwing Lisa against the walls in the bathroom that he really has his hand behind her head. It was later revealed that Cillian Murphy did this on purpose. In an earlier take, he accidentally knocked Rachel McAdams out and wanted to prevent it from happening again.
At the beginning of the film when Jackson Rippner's partner is going through Joe Reisert's wallet, he pulls out Joe Reisert's drivers license. The street address given is on Maryland Avenue, yet Jackson Rippner recites a different address to Lisa Reisert.
In the beginning when the agent announces that flight 1019 is ready to board, the jetway is not connected to the airplane. This can be seen through the window.
In addition to the different planes shown, the final exterior shot as the plane is taking off is actually a 737 landing. The flaps are clearly in the landing configuration and the reverse thrusters are on.
(at around 59 mins) Obvious stunt double when Lisa trips on the travelator in the airport.
When Lisa rams the hitman with a Jeep and launches him through the door, immediately after the camera cuts to the interior of the house cuts are visible in the wood of the doorway to allow it to break away.
When the plane is taxiing before takeoff the color is white with a blue belly. The engines are also a kind of off-white. As it is taking off you can tell the engines are now blue and they are shaped differently. During taxiing they are kind of long and skinny. During takeoff they look shorter and fat. It is obviously a different plane.
One of the stickers on the cab's windshield expires 04/02, Legislation creating the Department of Homeland Security wasn't enacted until 11/02 and the actual date for the creation of the Department of Homeland Security was March 1, 2003. In other words, the Department of Homeland Securty did not exist until March 1, 2003. As closely as cabs are regulated at the airport this seems unlikely for the cab to get by for so long with an expired registration or inspection.
(at around 1 min) The truck carrying the fish at the beginning of the film has an out-of-date Florida license plate, the kind that was issued between 1978 and 1985 and has long been obsolete. Also, there is no county name/"Sunshine State" on the bottom like all Florida plates have.
(at around 3 mins) When Lisa gives Cynthia her code to enter into the hotel computer, she says 7-8-8-4. When the computer screen is then displayed next the code that Cynthia entered is shown as 4-8-8-7.
The semi-arid, mountain view outside the plane when landing in Miami is clearly not Miami (which is green, tropical, and flat with lagoons nearby).
When Lisa tells Cynthia to put her code into the computer, she says "underscore L Reisert." However, on the computer screen it shows as "L_Reisert."
When Lisa is telling Cynthia to get all of the special items for Keefe's room, Cynthia asks if he's "Platinum Club", implying that she doesn't know who he is or how important he is. Later, however, when Lisa wants to switch his room, Cynthia says, "But he always stays in that room," making it seem like she does know about Keefe.