The sniper can travels from the departure level of LAX to the arrival level in about 20 seconds. That would hardly be possible in 20 minutes at most days and times at LAX.
For most of the film, Nora (Sofia Carson) wears a pair of stiletto-heeled boots, but when the action starts in the car park and she has to do a lot of running, they change to a block heel. They revert to stiletto once she no longer needs to run around.
Ethan enters the plane's baggage hold while it's still daylight. Moments later the Traveller is seen in the passenger cabin and the cabin is already in dark mode for the journey. The blinds are down, the cabin dimmed and the attendants about to serve drinks. At this time, the plane should still be climbing to cruising altitude in daylight.
There's almost no way of locating the aircraft that you are after on the tarmac without guidance from the tower.
Outside the flight to DC, a mother with her boarding pass is holding her child with hair. Immediately after the mother is seen boarding the plane holding a different child with no hair.
There is no way to open the door of a 737 cargo hold from the inside.
Only a very short person can stand up straight in the baggage hold of a 737 and then only in the middle. Average sized men could not possibly fight standing up.
The bag has a bypass key slot used by security. So getting the combination was not necessary.
Airport employees cannot simply enter a code into the keypad of each door. They must first scan their badge and then enter a unique entry code.
A random enhanced baggage screening would not be conducted by a single TSO alone in a sequestered room with the traveler. It would normally be conducted without the traveler present, and the bag would be searched by at least two agents to ensure multiple witnesses if the traveler faces criminal charges. The only time the traveler is required to be present is when searching a checked bag known to contain a firearm. Additionally, in a suspected security breach, the traveler would first be detained by law enforcement to ensure a prompt and efficient arrest if a security hazard is found. Most TSA agents are not sworn law enforcement officers and do not have the legal power to conduct an arrest; this is why uniformed police are invariably present at TSA checkpoints.
A TSA operative, as a Federal employee, would not be fired on the spot for allegedly being drunk on duty. They would be suspended pending a disciplinary investigation. In this case, however, no mention of termination was made. The most that the viewing audience is informed about is that the employee was sent home, most likely suspended until the aforementioned investigation.
When the cargo door is opened on an airplane a notification comes up in the cockpit. This would have immediately made the pilots stop and radio the tower, however in this case the notification is shown as well as the pilot missing it. I'm unsure if the actual warning indicator is supposed to stay on or shut off if the issue is fixed, but it is addressed.
The opening scene has a plane flying south over Santa Monica pier towards LAX. LAX has no north/south runways, planes always land headed west.
The coastline at the Santa Monica Pier is oriented northwest to southeast and the plane is heading towards the coast, so it is heading east-southeast, not south. Flight monitoring apps show that aircraft approaching LAX from the northwest routinely overfly the Santa Monica Pier in an east-southeasterly direction, make a broad right turn over Montebello, and then fly a westerly final approach to LAX. The airliner in the film appears to be flying lower than this traffic normally flies, but the basic flight path is accurate.
The coastline at the Santa Monica Pier is oriented northwest to southeast and the plane is heading towards the coast, so it is heading east-southeast, not south. Flight monitoring apps show that aircraft approaching LAX from the northwest routinely overfly the Santa Monica Pier in an east-southeasterly direction, make a broad right turn over Montebello, and then fly a westerly final approach to LAX. The airliner in the film appears to be flying lower than this traffic normally flies, but the basic flight path is accurate.
The ranks on the shoulder bars do not match the ranks on the name plates for some of the TSA officers. For example, Phil Sarkowski's name plate says "lead officer" underneath his last name. However, his shoulder bars have three stripes, which indicate he's a supervisor. Lead and supervisory officers are two different ranks in the TSA.
A gunshot in the cargo hold would have been heard by every passenger on board, leading confusion by the crew and panic in the passengers.
If the Traveller did manage to open the emergency door to parachute out of the plane before the bomb went off, that would leave the plane with a huge breach in the aircraft cabin, causing the air within it to constantly get sucked out. Meaning that when the bomb went off, all its gas would get sucked out of the plane before it could harm anyone, making his entire effort pointless.
The tech protagonist has piggy backed onto the security cameras and proceeds to position and zoom the cameras at will, but not one person in the actual TSA camera control room notices? Not likely..
There are no security cameras in public bathrooms, as that is illegal. Ethan could have simply gone into one of the employee bathrooms to call the police, send the text on his watch, or write the note, and the bad guys would have no way of knowing.
There is absolutely no way that if there was a bomb threat at an airport like LAX that they would only shut down 1 terminal. They would shut down the entire airport and ground all flights, whether or not it was a regular Tuesday or Christmas Eve.