Stupidity: When Johnny is captured by Roarke and his followers, Danny gives him the power of the Ghost Rider back. Roarke knows what Danny is doing, but doesn't order his men to stop him, or even attempt to stop Danny himself.
Stupidity: Jill wasn't thinking too clearly when she plans her story. She only wiped the fingerprints off the gun but they would be all over the tape on Trevor's body. Then she wipes off the knife yet touches it again to slide it across the floor. She was thinking that Trevor and Charlie were going to be thought of as the killers but their fingerprints weren't on either of the weapons.
Stupidity: In the scene when the cook is torched, why didn't he just jump out of the longboat into the water? Why get burned?
Suggested correction: It would be pointless. If he ran away, Blackbeard would just come after him and make him suffer greatly. At least the fire is quicker than torture or being zombified.
Hogwash. Fire is even more painful than torture.
Not only that but, it's only speculation what would Blackbeard would do to the man if he had survived.
Stupidity: As the movie progresses, we see the deranged killer, Martin, collecting a dozen victims for his Human Centipede project and depositing the victims in a sealed chamber. Every time we see the victims, they are nude, face-down (always in the same positions on the floor), struggling and moaning and sobbing. However, their hands are only duct-taped behind their backs, and their ankles are duct-taped. There is nothing to prevent these victims from rolling over, sitting up, standing, and even assisting each other to escape. Yet they never change positions or attempt to escape.
Suggested correction: The entirety of the film, save the opening and closing scenes, is intended to be a disturbed fantasy of Martin. As such, any inconsistencies or character mistakes such as this can be attributed to Martin's deranged mind. He is fantasizing about creating a centipede of his own and his fantasy is not detailed enough to include an explanation as to why his victims can't escape or help one another.
Stupidity: All the mutants on the island need Magneto at the last second to take control of the missiles so they don't land and explode. Why didn't Azazel just teleport everyone off the island?
Suggested correction: Given the situation, there was probably very little time to come up with a plan like this. The missiles were flying towards them extremely quickly, and there would have been nowhere near enough time to band every single person together for Azazel to teleport them all out of there in just a few seconds.
There was plenty of time. He could have taken 5 at a time down the Beach 3 miles and came back for the rest. Earlier in the movie he was moving so fast men were falling from the sky at nearly the same time and he was teleporting them one at a time.
Stupidity: There is a scene about a null hypothesis proving Cassius is the killer. Nearly everything is wrong in this scene. Statistically, you never prove a null hypothesis true. (01:23:11 - 01:24:22)
Stupidity: The protagonist has a sophisticated alarm system with cameras...that do not properly show who is at the gates (the cameras are positioned in a way that does not show the face of the person ringing). The bad guys are disguised as police officers...and wear ski masks, which would have made the disguise entirely pointless - but luckily for them, Nicholas Cage can't operate cameras nor looked at the ones on the entryway or the front of the house, didn't open the door sooner nor peeps before opening. They could not know any of that, though, just that the camera at the entrance has a terrible angle.
Stupidity: When Gail shoos Luke off the first day, in fact nobody accompanies him to the door and they discuss the evil plans when he's not even gone nor they even check he is, they just go ahead with the script. It's a rather odd dynamic, very rushed and movie logic-like. Or theater logic, since it's a typical 'exit stage left' moment.
Stupidity: In the opening scene, Sonny has come to her now-deceased father's house. Police and the coroner are in the basement taking notes while standing around the body - which is face down and awkwardly lying at the bottom of the steps. Det. Sabatino informed Sonny that the death was ruled accidental due to a high blood-alcohol level. Detectives or the coroner did not rule out other possibilities: natural cause, suicide, or murder. High blood-alcohol level could be secondary.
Stupidity: While the train cars are still derailing in front of them, the kids stay on the porch and actually start running toward the oncoming train. Next, they turn around and run in the opposite direction, while staying the same distance away from the train tracks and flying cars/debris. When they run out of the porch to stay parallel to the train, they again turn around and run to the middle of the porch and look like they are jumping around together, clueless where to run to next - running in either direction parallel to the train was not getting them away from derailment. Then they disperse in various directions but stay off the porch. (00:17:24)
Stupidity: Spoiler alert. After the son makes it out, he could get a rescue team to get his dad by going in where he came out.