In the opening sequence when we see Monica surrounded by a group of people, the guy later on called Tyler is laying down flat on a lounge chair and he's wearing a pair of sunglasses and a bathing suit. But right after the man says, "Tyler here's half-fish.", Tyler sits up and is suddenly wearing a shirt, but before he was wearing no shirt in the close-up view.
When Agent Sharpe is investigating the wreckage in the beginning, as he walks past the destroyed car behind him, there is a piece of it on the left that's burning. Then, when Sharpe looks inside the back of the truck, there is another piece that's burning on the right, but there was no other piece burning on the right side of the wrecked car. Then when the scene cuts back to Sharpe, the piece on the right is missing again, but when he picks out the python's scale in the back of the truck, it appears again.
When Eve is having difficulty reloading her gun, Broddick comes over and kisses her with her hands still on the gun. In the next shot, however, her right hand is still on the gun, but her left hand is on Broddick's cheek as they're kissing.
When Monica and Emmett see Betty and the python having sexual intercourse on Monica's GPS monitor, right after she says, "I don't think you wanna see this.", she's holding the monitor up to her chest. But, in the next shot, she's holding it away from her chest for Emmett to see.
During the scene when Monica and Tyler are competing to see who can hold their breath underwater the longest, when Tyler submerges, Monica clearly isn't wearing her tang-top, but has it on later in the next few shots.
Snakes do not growl nor do they roar.
At 25:21 the snake expert calls a snake poisonous.
The various weapons seen throughout the film are to light caliber to fight the giant snakes in the film. The weapons should have been much bigger and more powerful.
Broddick's black and gold Boeing 747 airplane is obviously CG throughout the film.
In the beginning when Agent Sharpe discovers a hole in one of the access tunnels to the water treatment plant made by the python, you can see the hole is slightly small on both sides of the door. Judging by the python's size as the movie portrays, the hole would've been made much bigger than how it first appeared.
In the scene when the soldiers have wandered off too far in the facility and start shooting at Betty, you can hear their guns firing, but if you look closely, there are no bullets being released from their guns.
During the final scene when Betty and the python are battling each other on the subway tracks, a train comes down in the middle of them. Once it comes down, the sound of a car horn can be heard despite the fact that it's a train coming down and not a car.
When Broddick and Eve first see Kent speaking on the news reporting the destruction of Ramon's convoy, you will see his mouth doesn't correspond to what he's saying, until he says, "...earlier this morning."
When the troops are driving to Philadelphia, a man sitting in traffic screams out, "Asshole!", but his mouth doesn't move.
When Tex has been killed by the python, and Mr. Foley tells Broddick, "When I got back here, he was gone!", Broddick starts saying "Mr. Foley..", but his mouth doesn't move in the first shot when he says it.
When Ramon tries to kill the python by detonating a bomb, in the beginning of the film, one of the men is grabbed by the python and accidentally shoots Ramon. The cable that's holding the man up as he's being attacked by the python is visible right before he shoots Ramon.
When the python has entered the water treatment facility and attacks one of the workers, as he's being pulled by the python, you can see a soft mat right underneath him to pull him as he's being dragged.
When Broddick begins fighting back at the python with his flamethrower at the disco, right when Emmett and Monica turn and look at him, in the next shot, two crew members can be seen running past Broddick from behind him.
Crew and search lights are reflected in Mr. Foley's black sunglasses in the scene when he is arguing with Broddick while hunting in the forest.
The movie takes place around Philadelphia, but the subway station they are in has signs for "Government Center", "Bowdoin", and "State Street", all locations on the T in Boston.
During the scene when the water starts coming down the flood tunnel, as Emmett and Monica are leaving, Emmett yells out for one of the hunters, James, to come along with them. But, instead, James just stands there and is killed by the water coming down. He saw the water coming towards him, so then why didn't he move to escape with Monica and Emmett?