Continuity mistake: During the boat chase, after the one boat blows up, another comes up behind Jones and Elsa. Jones starts turning the boat. In the next shot, the man in the boat behind them is shooting at them. They're not turning, they're going straight.
Visible crew/equipment: After Indy and Henry have escaped from Castle Brunwald, Indy jumps into one of the boats, pulls the motor starter cord and jumps back out, then just as he bends over to release the boat from the piling, right between Indy's legs the black covered arm of a hidden crewmember appears from under the tarp taking hold of the throttle, steering the boat away from the pier. (01:02:40)
Factual error: At the end of the classroom scene, Indy gives Marcus the Cross of Coronado. There is a pile of books on Indy's desk that he laters picks up and takes with him. One of the books (with the whitish spine, under the red book) is "Living Egypt", written by Paul Strand and James Aldridge. This book wasn't published until 1969, over 30 years after this movie takes place (1938). (00:15:20)
Factual error: When Indy is being chased by the tank there is a type 82 Kübelwagen - they weren't produced until 1940 and the movie is set in 1938.
Visible crew/equipment: When Young Indy is trapped in the train car with the lion, he tosses up the whip to Fedora, and as he's being pulled up in the interior shot, he's wearing a stunt apparatus around his waist above his beaded belt. [The stunt double is also wearing a glove on his right hand holding what looks like skewered meat, to presumably draw the trained lion, but that's a lot harder to see without pausing]. (00:08:35)
Deliberate mistake: While Indy is fighting the tank commander, he looks up to see them heading toward a cliff. After the tank goes over, from the time his companions look over the cliff to the time when they walk away and Indy is sitting on the ground, you can see the wind blowing in their faces. But as Indy starts to get up, the wind blows his hat toward him, which it couldn't do as his hat flew off quite a while before, and the winds would have blown it far from the cliff's edge.
Continuity mistake: When Indy comes face-to-face with Hitler he hands over Henry's diary with its black elastic around the back cover, but in the closeup as the signature is being signed the elastic is around the front cover, then it's around the back cover again when Indy takes the diary back.
Continuity mistake: When Sallah rides up to the tank to rescue Henry we see Indy toss the whip over the side of the tank, but after the tank falls over the cliff, when Indy climbs back up then walks over to stand between Henry and Sallah the whip is coiled and back in its place, hanging from his belt. Even Indy can't do that. (01:36:00 - 01:37:40)
Continuity mistake: When Indy and Vogel are fighting atop the tank we see the soles of Vogel's boots and there is a red hexagon dot under each heel, but while Indy is hanging off the tank's side mount gun the soles of Vogel's boots are different.
Other mistake: While Indy and Henry are aboard the zeppelin Indy tosses Vogel out the lounge window, and when Vogel shouts up to the departing airship, in the next exterior shot we see the zeppelin airborne against a scenic view. Later, when Indy realises the zeppelin is turning around it cuts to another exterior shot of the airship, and the scenic view is identical to the earlier shot, only it's been flipped. The images of the zeppelin facing two different directions were composited onto the same scenic background.
Continuity mistake: When Indy shoots the three soldiers on the tank they fall sideways but not off the tank, a few seconds later all three bodies have disappeared.
Other mistake: Indy has been very careful to hide from everyone that Alexandretta is the city where the trail starts, only to give away all the essential info. He did not tell Elsa. Only Marcus (who has the rubbing of the crucial inscription) and Sallah knew. The only way that the Nazis find out is because he tells his dad, in a room which he KNOWS to be wired, i.e. bugged. (The Nazis also find the diary, but we know that the city isn't in there.) Stupidity doesn't quite cover it.
Revealing mistake: When Henry says "Faster, boy, faster!" to Indy when they are driving into the tunnel to escape the flaming aircraft, you can see the track that the flaming aircraft is sliding on.
Revealing mistake: When Indy shoots three Nazi soldiers with a single bullet during the tank chase sequence, you can see the blood packets inside their uniforms.
Audio problem: When Vogel is holding Elsa hostage in the castle, he points his gun at Elsa's neck and says "Enough, she dies." If you look at Indy's shadow on the wall, you can see Indy is mouthing the word "Wait." In the next shot, he is saying the word again, this time with audio intact.
Visible crew/equipment: After Indy's father is cured and the Nazis drop the weapons, he stands up and set lights are reflected on his glasses.
Continuity mistake: When Sallah pulls his rifle and overtakes the Nazis at the Great Seal he is in the forefront with the Nazis in front of him and Indy and his father are behind him. Within the next scene he is now in the background with his rifle resting in his arms.
Continuity mistake: When Indy is pouring the water from the Grail onto his father's wound, we see him pour all the water out. When his father takes the Grail, there's now water left inside.
Factual error: The stamps on the mail at Sr. Jones house are Texas Statehood issued in 1945. A bit late for the scene. (00:24:15)
Continuity mistake: Onboard the ship at the end of the prologue, after Indy grabs the cross before it falls over the side, the guy in the white suit climbing up the steps. He's only reaching the top as the shot changes. In the next shot, he's already a few steps away from the top of the steps, telling his men to stop Indy.
Suggested correction: Automatic refilling seems to be the least of the miracles the Grail has performed.
LorgSkyegon
There was no evidence of this, plus we never see it refill before or after. How would it be empty when they first find it if it miraculously refilled itself? This is a poor correction just to make a correction.
Bishop73