Continuity mistake: The plane they are on changes several times throughout the movie. When it is sitting at the gate in Dallas, and while being pushed back from the gate, it is a Boeing 737. When it is shown taxiing out, it is an Airbus A320. Air to air shots are of a Boeing 767, which is also the same as the interior shots all throughout the movie. The 737 and A320 are narrowbodies, while the 767 is a widebody, commonly configured 2-4-2 like the interior in the movie.
Revealing mistake: When Lisa stabs Jackson in the throat with the pen, if you watch closely, you can see that she is still holding the pen when she pulls her arm back, but in the entire rest of the scene the pen is still stuck in his throat. If you watch it in slow motion, the mistake becomes even more obvious.
Continuity mistake: When Lisa is on board the plane, she is wearing stiletto heels (best seen when she is collapsing in the bathroom). However, when she is running through the airport, she is wearing flat shoes. This is most easily seen when she comes of the transporter belt, when she trips and one of her feet swings into the air. Later, when she kicks Jack on the stairs of her house, she is wearing stiletto heels again.
Continuity mistake: After Lisa pretends to be reading a magazine to avoid the security guards who're looking for her near her gate, she spots Jackson and you can see two men sitting at a table eating lunch in the foreground of the shot. When Jackson sees her and starts running after her, both the table and the men are gone (Jackson runs through the place they used to be).
Continuity mistake: When Lisa is changing her top in the bathroom you see the cut on her chest and it is red almost as if it was only recently done or had been bleeding. Later in the film when Jackson is in the bathroom and he sees the scar it is healed up and there is now a fully healed scar. There are two problems, firstly the cut could not have healed in the few hours between when we see it. The second is that the cut we see at the beginning was said to have been caused two years prior. Therefore how could the cut be that fresh?
Factual error: The timeline for this film is incorrect. The flight Lisa takes is a red eye from Dallas to Miami. Non-stop flights between those cities takes 2 1/2 hours. Even with the west to east time change, this isn't long enough for a red eye. Shortly after take off, the clock in her father's house reads about 11:15pm. The plane lands after sunrise in Miami.
Continuity mistake: After Lisa manages to steal a car away from the couple at the airport, we see her try to make calls from Ripner's cell phone. After the cell phone blinks "Low Battery" for the first time, we can see that she is wearing a seat belt. Lisa then swerves to miss an oncoming car, and we see her hastily fasten her seat belt, as if it was never fastened before.
Plot hole: Lisa calls Cynthia and tells her to pull the hotel's fire alarm, which she does. Cynthia then physically goes up to the Keefe's suite to warn them something is wrong. Even though the fire alarm was pulled and it can be heard blaring in the lobby, the Keefes and the security team seem to have no idea that there is a problem until Cynthia knocks on the door and tells them to get out.
Continuity mistake: Jack's hairstyle changes throughout the film. The first shot of Jack in line shows a different style than any other shot in the film. Variations of styles with hair over forehead occur throughout, but hairstyles from different camera angles on the plane change from hair over forehead, to center part neatly exposing the forehead.
Continuity mistake: Characters' head positions change throughout movie. This starts from the first shot from Jack's left side, as they are in line for the counter. Jack is either reading the paper, or looking ahead, or to the left from Jack's right side. When the scene is filmed from the left angle Jack's head position is often the opposite. On the plane both Lisa and Jack show continuity problems in head position. Often the heads are forward, or toward each other when shot from the left angle, then facing each other from the other angle, without time or reason for the transition.