Plot hole: The snakes are contained in the cargo hold which is shown to be unpressurised on this aircraft (there is an altimeter which releases the snakes after it hits 35000 feet - if the hold was pressurised it would level off at cabin pressure, which is about 8,000 feet). A cargo door is left open to allow the snakes into the passenger compartment, but this would either cause the plane to not pressurise properly, causing everyone on board severe breathing problems if not worse, or would keep the hold at cabin pressure, meaning the altimeter would never reach the right level to release the snakes.

Factual error: One of the subplots involves a young boy ("Tommy") who is bitten by a cobra and the attempts to save his life. When they are working on his arm, it is horribly swollen & filled with fluid which they drain by cutting open his arm. Cobras secrete a neurotoxic venom which attacks the nervous system. It would not cause noticeable swelling at the bite site. The symptoms Tommy has would indicate a bite from a snake which secretes a hemotoxic venom (such as a rattlesnake), which attacks the blood stream & tissues, causing swelling.

Continuity: When the couple honeymooning die, the man gets sprayed by venom in the eyes, and begins foaming from his face in the close-up shot. However, when the camera cuts to a wider angle shot, the foam suddenly disappears.

Deliberate "mistake": In many of the non-CG generated snake shots, what appears to be a very venomous coral snake is in fact either a scarlet king snake or a California mountain king snake (depending on the shot). These are much safer, non-venomous alternatives for filming with the actors. Look for the ordering of the colored bands (red/black=venom lack, red/yellow=kill a fellow).

Continuity: When the snake attacks Sean at the end of the film and Flynn shoots him and the snake, the snake disappears completely.

Continuity: The size of the hole that is made in the side of the aeroplane in order for them to land the plane changes from growing larger and larger, to smaller in wide side shots of the plane, then back again, etc.

Continuity: When Sean is being interrogated by Flynn, Flynn puts a plastic evidence folder beside him on the table, with a can of Red Bull inside of it. During the interrogation, the folder changes position a few times.

Factual error: When they track the down the snake keeper that had the snakes he was bitten. The snake expert went into the fridge for the antivenin and it was already mixed in the vial. He then loaded a syringe with the antivenin. This is a major flaw. Antivenins have to be mixed. They are never in a vial ready to go. They are always mixed and warmed in a solution prior to administration.

Continuity: There are times when the interior of the plane is plunged into complete darkness for long periods, yet all exterior shots of the plane show the interior lights on.

Continuity: Troy is the first passenger to exit the plane, yet in the next shot he is spotted walking down the stairs behind Neville Flynn. It's easy to spot him by his orange shirt.

Factual error: When the second toilet victim enters the plane's toilet, the overhead light is already on. In a normal airplane situation, the light only comes on once the door is locked.

Factual error: When Neville Flynn is going to reset the breaker for the A/C he is in the cargo hold. He moves aside a shipping container, a unit load device (ULD). This unit load device had a big sticker across the top of the side. All ULDs are required by FAA regulations to have the identifying number on all four sides at the highest, most visible point. There was no identifying number on the front and there was none on the side. Where one belonged there was a big Pacific Air sticker. This was more than likely covering up the ULD number that was borrowed from another airlines.

Continuity: Early in the movie, officer Brown is saying goodbye to his two kids on the plane. His hand moves from the inside to the outside of his pocket several times between shots.

Plot hole: Towards the end of the movie where the passengers are moving upstairs to the first class cabin, people start pulling down carry-on baggage to blockade the snakes, before the flight attendant thinks about using the raft as a protective shield. You can hear someone calling for the luggage, as well as see people pull it out of the overhead compartments. The problem is that there can't be that amount of carry-on baggage in first class, everyone but the FBI agents and Sean were bumped down to coach, and given how underbooked the flight is anyway it can't be that they ran out of room for it all downstairs.

Factual error: When the flight crew declare a mayday, they talk to LAX tower. However, the tower's radios wouldn't have the range to receive these transmissions as the tower only controls the airspace directly around the airport. Likewise they would actually be talking to Oakland Oceanic Control (not Oakland Area Control Centre), as the sea area between the Western Seaboard and the Hawaiian islands falls under Oakland's FIR (flight information region), and thus the flight is their responsibility.

Factual error: The plane being used is a Boeing 747. The first class cabin is upstairs, yet shown to have two aisles. The upstairs cabin in a 747 has only one aisle.

Factual error: When the couple go into the restroom to have sex, they dis-engage the smoke detector, yet nothing happens. The pilot and the stewards would have been notified by alarm that the detector had been tampered with.

Deliberate "mistake": When the snakes attack, we see a woman open an air sickness bag and a snake jumps out of the bag and strikes her. Though an impressive scare, that is impossible - the snake could not have crawled into the bag without her noticing it.