
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.
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)
Factual error: The interior of the German U-boat is completely different from the real interior of a Type VII U-boat, which is correctly shown in movies like 'Das Boot' or 'U-571'. For example, the ladder from the conning tower faces a different direction, the map table is too big and on the wrong side, the valves for submerging are on the side of the control room and not at its front and stern, depth gauges are too big...etc. All interiors were standardized, so it could not have been an individual build.
Character mistake: When the crew of the German U-boat boards Katanga's ship, the submarine moves in a position perpendicular to the ship's bow as if to block its path. In reality, this would have been a pretty stupid move by the German captain, as Katanga could have rammed the submarine easily. Any kind of damage to the hull, especially ramming damage (even from small ships), would have been catastrophic to the submarine. It makes no sense to make a manoeuvre like this.
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.

Revealing mistake: When Indy is fighting the big German at the base of the airplane, Indy reaches down and grabs a handful of sand to throw in his face. You can see the finger marks in the sand from a previous take.
Audio problem: When Marion meets up with Indy on the steps of the building at the very end of the film, she asks what was going on in there. Her first few lines of dialogue were dubbed in after shooting. Her mouth isn't moving with the dialogue.
Continuity mistake: When Indiana is fighting the Big German mechanic by the plane, the plane goes around in circles and the wing tip of the plane punctures a hole in a petrol tanker that is parked near by. This causes the petrol to gush out of the tanker and you can see that ground underneath the plane gets totally drenched with petrol. But in the later shots, the ground under the plane is dry. There is also a shot where you can see the tanker in the background not pouring petrol any more and all you can see is a little wet spot around the tanker. (01:18:45)

Revealing mistake: During the truck chase scene, Indiana is thrown or forced over the front of the bonnet and almost run over. There is a wide camera shot, and while holding on to the front fender, Indiana can be seen sitting on a chair which is attached to the truck. (01:27:40)
Revealing mistake: When we have the exterior shot of the ship that Harrison Ford, Karen Allen, and the ark are aboard, even on the DVD can be seen specks of dirt over the view of the ship and the ocean - obviously it was filmed through the window of another ship. (01:31:35)
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.

Continuity mistake: After Indy replaces the idol for a bag filled with sand, the position of the bag changes between frames.
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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