Revealing mistake: When Indy and Willie jump out the window at Club Obi Wan, just as they crash through the glass note the white stunt leggings/knee-pads on Willie's legs above her shins. Willie's legs are bare when she lands on the lower awnings.
Revealing mistake: During the mine cart chase, when Short Round's arms are being pulled by the Thuggees while Indy's hanging onto him, in the side wideshot you can see the black safety strap around Shorty's hips, over his pants.
Revealing mistake: Indy's bridge breaks and he is hanging by it with the natives shooting arrows at him. If you look closely you can see two arrows bounce off his back. All the other clatter noisily onto the cliff-face or stick in the bridge, so it's not like they've lost much force due to the range. (01:48:40)
Revealing mistake: During the chase with the carts in the mine, in some of the shots, you can see that figures who are supposed to be Indy, Willie and Short Round are dummies. Indy's arm especially belongs to a mannequin in the shot where the cart almost derails. (01:36:00)
Revealing mistake: When Indy and Willie jump out of the Obi Wan Nightclub, they fall through several awnings, the idea being that they will break the characters' fall. All well and good. But, if you look very carefully, you can see small taped-up cut marks which the crew made so the stunt men (and women) could effortlessly glide though the awnings.
Revealing mistake: To escape the Obi Wan Nightclub, Indy and Willie jump out the window and fall through several awnings. When they hit the second to last awning, there is a close up on the actors. Just before they hit the awning, there are butt-shaped indents in the fabric from a previous take.
Revealing mistake: At the end, the elephant that the kid is riding sprays Indiana and Willie with water. If you watch very carefully, Harrison winces in anticipation right before the water hits them. (01:52:30)
Revealing mistake: During the mine cart scene, after Indy notices that the track cuts out, just as the mine cart flies over the expanse there's a vertical wire at the back of the cart, leading up to the top of the screen, and a horizontal wire at the front of the cart, leading toward the right side of the screen. Additionally, when the mine cart lands on the other track keep your eye on the top edge of the screen as something dips into view, but it's pulled back up immediately, right before the shot cuts away to Mola Ram. The wires and the mysterious object can be seen when viewed on Amazon Prime, but they seem to have been edited out of the DVD (2008 version) I own.
Revealing mistake: When the second band of Thuggees are in the mine cart pursuing Indy's cart, note the metal bar attached to the back of Indy's mine cart which wasn't there before, for use during the ensuing stunt. That bar then disappears and reappears.
Revealing mistake: During car pursuit, when the Chinese thugs drive into the food stands and two of them fall onto the tables, you can see that at least one of them is a puppet from the way his arm is rigidly sticking out when he has fallen. It should have fallen to his side. (00:11:45)
Revealing mistake: During the "Anything Goes" dance number, the shot of the dancers doing the 'splits' is simply ran in reverse to produce the illusion that they're rising up from the stage floor.
Revealing mistake: The skull which Indiana forces under one of the wheels in the spiked room's ceiling has a very straight, clean-cut line through the cranium. It has none of the imperfections or signs of growth which would occur naturally; this is a very fake-looking skull.
Revealing mistake: In the wide angle of the mountain where Indy, Willy and Short Round lean on, they cast no shadow, revealing it's a composite image.
Revealing mistake: When leaning against the mountain, in the wide shot Short's face turns totally black, Willie becomes semi-transparent, and Indy's chest becomes greyish colour, all because of the blue-screen effects.
Revealing mistake: When the yellow raft slides down the snow, in the close-ups it turns white because of the blue-screen effect.
Revealing mistake: When the rickshaw crashes, neither the driver nor the girl move at all. Instead the sailor stands up by his own means and jumps, which is a really bad stunt.
Revealing mistake: During the mine chase, after Indy cries to Shorty "Let it go, our only chance!" the wig of the doll replacing Willie flies away. (01:35:59)
Revealing mistake: When Indy is hanging off the bridge and is punched by Mola Ram, Indy's safety wire attached to his belt is very noticeable. (01:47:45)
Revealing mistake: When the plane lands against the snowy mountain, no parts fly all over and no snow shatters at all, revealing the composite trick.
Revealing mistake: When the water floods the mine, some shots of the 3 heroes are an obvious composite of their blue screened image over a set. Problem is, when Indy tells the two to run towards a tunnel on the right with a log blocking the way, Indy and Shorty run through the log as if they were ghosts.
Chosen answer: His neck was snapped by the whip getting caught in the fan. There isn't always blood with a hanging. Since the fan wasn't designed to hold a man's weight, the motor in it would have stopped or given out.
Captain Defenestrator