Character mistake: Towards the end of the film the Jackal, in disguise as the fictional one-legged, grey haired Frenchman Andre Martin, finishes setting up his sniper's nest and removes his beret, revealing that he has only dyed his hair grey where it protruded. He has a circular mop of his normal chestnut brown hair under his hat! This is an incredibly stupid thing to do - it is a perfectly normal thing for a policeman (or any other security operative) to ask that someone showing identity papers remove his hat if he is wearing one. The Jackal is a professional assassin who meticulously prepares for all contingencies - he isn't going to throw away his whole plan for the sake of a bit of extra hair dye. (02:10:05)
Character mistake: A TV news announcer describes Alan Shepard's first manned launch into space as him being lifted to "an altitude of 116 miles per hour." That's not an altitude, that's a speed. It should have just been "116 miles."
Character mistake: At the beginning of the scene where the vampire hunters leave London in pursuit of Dracula, Jonathan narrates, "By train we can reach the Romanian port in Varna in three days." However, Varna was (and still is) a Bulgarian seaport (this can even be seen on the map showing the Turkish invasion of Eastern Europe in the movie's prologue, and on the map that Jonathan studies aboard the train at the beginning of the film). (01:45:35)
Character mistake: When Whip is in the hospital, standing straight in front of the camera is a ridiculous nurse; she takes down the empty IV bag and pulls the bag away from the IV line, she drops the bag on the floor, a big no-no, but try as she might she can't seem to get the spike to go into the new bag. While she's doing all this, she's waving that sterile spike everywhere, touching everything she can, including herself, and picking up germs that will go straight into Whip's IV line, and into his body, when, finally she gets that infected spike into the infected new bag.
Character mistake: When Lisa is taken to the hospital, she tells Kathy that she saw the ghost of Jodie DeFeo. The name of both of the DeFeo's daughters wasn't Jodie. Their names were Dawn and Allison. Jodie was the name of a demonic pig that the Lutz's daughter Missy had befriended.
Character mistake: It's all very heroic and manly but the effort put into dragging the Phoenix into its takeoff position once the engine is started is totally wasted. Townes and A.J. are both experienced pilots and Elliott is supposedly a genius aeronautical engineer - they must surely be aware that the engine power required to taxi an aircraft is trivial compared to that required to lift it into the air. Even taking into account the drag of the skids and wheels, if that engine cannot propel the aircraft at a few kilometers an hour on the ground it cannot propel it to take off speed, nor keep it up once airborne. They are not there to steer the aircraft - they are taking the strain of the whole weight of the air-frame, dragging it into place, and the energy input of eight exhausted, underfed people would add nothing to the contribution of a 2500 bhp aircraft engine in moving the Phoenix. They are not trying conserve fuel - they had enough fuel for an extended flight with both engines at full throttle, so they have easily enough to run one engine throttled back to reduce stress on the air-frame, which they say they are going to do.
Character mistake: In the court scene Clyde mentions a case, Day v McDonough docket number 04-1325. This is a real case, but the docket number is 04-1324.
Character mistake: In the scenes in San Diego, all the scenes outside the sub are taking place during daylight hours. Immediately after the crewman relays the message about the mysterious telegraph transmission, the scene shifts to the sub. The commander asks what time it is in Melbourne and is told it is 1500 hours (3PM). But if it were that time in Melbourne, it would be 10PM in San Diego, and thus not during daylight hours. (01:33:30 - 01:38:05)
Character mistake: During the dancing girl scene, as they are singing the praises of Kane, the girl to the immediate right sings out of time with the rest of the dancers during the line "His favorite son." Even though she forgets to sing the line, she can be heard singing it a bit too late. (00:41:00)
Character mistake: At the beginning of the movie, the German sub gets surprised and severely damaged by a destroyer. The sonar man first notices the enemy destroyer approaching, but only a short time before the destroyer is already literally on top of the sub. German sonar at the time had the capacity to detect ships up to more than 7 miles away, so the sonar man really had to be asleep at his sonar station not to notice the destroyer approaching. (00:03:40)