Revealing mistake: When the German staff car comes into the market place to find no truck, watch as Dietrich hurls the melon - the SS guy in the front is obviously a dummy for this one shot. (01:29:40)
Continuity mistake: Several times during the fight in and around the truck the bars around the top of the cab come off and are miraculously back on again. (01:24:05)
Revealing mistake: When Indy and Marion are being sealed up in the Well of Souls, You can plainly see Marion counting down (she is mouthing the numbers) to the cue for her to scream as the Well is sealed. (01:12:20)
Factual error: The truck that turns over and blows up after Indy shoots the driver is a Mercedes Benz L701. It began production in 1944, and this movie is set in 1936, so the truck is not period correct. Also, the alleys are too narrow to allow this truck to turn a corner.
Revealing mistake: When Indy fights the driver of the Nazi truck, the windshield is smashed when Indy is thrown through it, but there is no wind. Look at the driver's hair, not one stirs from a breeze while driving a fast moving truck with no windshield? (01:27:30)
Revealing mistake: When Indy is running through the cave and finds the spy that took the artifact with spikes through him, he brushes up against the dummy and it shakes like rubber and the light bounces off it like rubber. (00:09:10)
Continuity mistake: At the beginning of the film, When Indy uses the whip to take the guides gun away, Satipo makes a weird face and starts to move away in amazement. The very next frame, in a wider shot, he is not finishing his movements, but on the contrary he is standing still, with a normal gesture, until a second later he starts to repeat the movement and looks from before.
Continuity mistake: When Indy is fighting the Nazis on the truck, one Nazi is thrown from the truck and is rolling the opposite direction of the truck. (01:23:30)
Factual error: During the travel to Nepal, "Thailand" is written on the map. The country has had this name only since 1939. This film takes place in 1936, when Thailand was called Siam. (00:23:20)
Continuity mistake: After Satipo runs with the idol, Indy grabs a root to help him climb up the ledge. Half a second later, from a different angle, the root is meters away and he is grabbing it again, repeating the whole scene.
Continuity mistake: Just before the car carrying Marion in the wicker basket explodes in the alley, Indiana shoots a man twice in the chest. The man has blood stains on his shirt before he is shot.
Continuity mistake: As Indy and Marion are starting to run from the plane, you can see the yellow wheel chocks are back in place under the plane's tires.
Continuity mistake: After Indy steals the idol, while he is hanging in the well, in the front angle his left leg is bent and already outside, in a quite comfortable and secure position; yet in the angles from behind both legs are inside, hanging loose.
Continuity mistake: After hitting one thug, Indy jumps out of the way of one trying to spear him, leading to the one behind Indy getting run through. As the guy gets run through, he is in front of a hanging string of fruit, with the stacked fruit to his right. After a cut scene to Indy and Marion running away, the run through thug is now facing the fruit stand, setting up the sight gag of the blade sticking out with two fruits stuck on it.
Continuity mistake: While Indy is in the Well of Souls, Belloq greets him and is standing by one of the four sides of the rectangular hole. A frame later he stands by one of the corners.
Continuity mistake: After grabbing the idol, the cave starts to collapse, filling the place with rocks and rubble. When Indy starts to run, from the angle behind the floor is clean, rocks starting to fall for the first time.
Continuity mistake: Satipo drops the whip half a meter away from the closing gate, then runs away. However, when Indy rolls underneath the door, the whip is laying right next to it.
Continuity mistake: When Indiana is hiding his face with the cloth, watch as he enters the tent that Marion is being held prisoner in - at first, Indiana has to hold it in place; in the next shot, he has it tucked into the rest of the folds. The next shot, the actual position of the cloth changes.
Factual error: At the beginning of the movie, Indy escapes in biplane with registration OB-CPO (a Star Wars nod, as noted in trivia). However the OB registration is used by Peru, and it should be followed by four digits, not by three letters. (00:12:10)
Revealing mistake: The Pan American aeroplane Indiana Jones boards in San Fransisco looks similar to (but has noticeable differences from) the Boeing 314 PanAm used for transpacific flights. This aeroplane did however not fly until 1938 and at the time of the story the company only flew transpacific with Sikorsky S-42s, an aeroplane with a completely different body than the one used in the scene.
Answer: Indy and Marcus Brody believed that the Ark needed to be studied. They certainly didn't want to put it back where it was found. They believed that the U.S. government would find the best archaeologists, researchers, and scientists in the world to study the Ark. They are both upset that instead, the government has decided to simply lock the Ark away. This is why Indy says, "Fools. They don't know what they've got there," as he is leaving the building.
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