Other mistake: At the beginning of movie when Indy is about to steal the gold idol, the camera does a close-up of it. The idol has been in a decaying temple for hundreds of years. but it appears shiny and new, as though just placed there. You'd expect the idol to at least be dusty or covered in jungle debris.
Revealing mistake: When Belloq's head explodes, the actor has been visibly replaced by a dummy.
Continuity mistake: After Indy replaces the idol for a bag filled with sand, the position of the bag changes between frames.
Other mistake: During the truck scene, after the German soldier hanging onto the door falls down and another guy crawls over the roof, palm trees are reflected on the windshield, but wide shots show not a single tree around because the palm trees area was left behind a while ago.
Continuity mistake: When Indy and Brody meet at the University with the two government officials, a group of rolled maps or plans are placed on a podium horizontally. Halfway through the scene, they are all laying vertically.
Continuity mistake: During the shooting at the bar, Marion covers her ears to muffle the sound, but a frame later they are around the wall in front.
Continuity mistake: Indy climbs on a plane's wing, and a German mechanic arrives and asks him what he's doing, raising his left arm and ordering him to approach. A shot later, the arm is down.
Continuity mistake: In the map room, after Indy has discovered where to put the stick in, the sun rays lights the head and shoulder of a painted figure and the whole body of the figure to the right of it. A frame later the first figure is now completely lit. Too fast a change.
Audio problem: In the bar, when the man is shot in the face and burns alive he screams in pain, but he never opens his mouth.
Revealing mistake: When the Nazis are about to glow (and die), check the one on our left. His shirt is already unbuttoned right where the light will subsequently glow (which was a mere light bulb). A second later, he triggers a device clutched in his right hand (seemingly a switch) seconds before his chest lights up. (01:47:25)
Deliberate mistake: When Indy and Marion are sealed in the well of souls, they are completely cut off from the outside world. As such, other than the torches, it should be pitch black, but it is surprisingly well lit in there.
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 the plane takes off in the beginning, Indy sees the snake. His hands are grabbing at it, but a second later his hands are on the rim of his cockpit.
Continuity mistake: When Indy is driving the truck with the ark, a German tries to get in on the right side. Indy kicks the door open twice, and after the second time the top hinge of the door gives easily. The guy is half way dragging on the ground, holding onto the now askew door. Then in the next closeup, the door is hung correctly with the guy on it, and Indy kicks it again. The guy goes dragging again, and then he and the door fall off.
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: In the submarine dock of Geheimhaven, Captain Mohler is a man with dark hair in his mid or late thirties. But during the procession, he seems to be much older, with grey hair.
Factual error: There's absolutely no way Sallah and Indy would be able to lift that 'lid' (for lack of a better word) off the ark. That thing is solid rock and would weigh close to a metric ton - and none of them look like professional deadlifters to me.
Factual error: When Indy is attempting to steal the Ark when driving the truck, one of the soldiers shoots him in the arm. Then another German punches him repeatedly in the same arm, causing Indy great pain and injury. After suffering a wound like that there's no way he'd be able to move that arm, let alone raise it above his head. But the next day after the boat is stopped by the sub, Indy jumps into the water and swims to the sub without any problems.
Continuity mistake: When Indy stands inside the Map Room, looking at the model of the city, the rays of the sun are to his left, and they move right and down as the sun rises. But since the entry hole is behind him, that would mean that the sun would be to the right when standing outside - but it was to his left when he entered the hole.
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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