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.
Factual error: In this film, and in Raiders of the Lost Ark, the German vehicles are marked with the DAK (Deutsches Afrikakorps) symbol (a swastika over a palm tree.) The DAK and its symbol were not created until 1941 when Hitler tried to rescue his Italian allies in North Africa. (00:56:15)
Continuity mistake: In the temple in the Canyon of the Crescent Moon, Indiana Jones rushes to his father's aid with the Holy Grail filled with water. He is shown pouring every last drop onto his father's wound by turning the Grail upside down, yet another camera angle shows his father clutching the grail to his chest, and there's still a bit of water in it.
Continuity mistake: At one point Indiana's father blows the tail of the plane in which they were flying to pieces in an attempt to shoot at the Germans. This is obviously in a close-up studio shot. The next moment the plane is shown flying in the distance with its tail still intact. (01:17:45)
Revealing mistake: During the "What happens at 11 o'clock?" joke, Jr. counts down ("12, 11, 10!" or something like that) with his hand, matte lines surround his hand to the point where it almost disappears.
Continuity mistake: While Indy and Marcus are in the apartment in Venice, after Marcus says, "He knew everything, except the name of the city", he slams the diary shut. Then it's shown open, and he closes it a second time. When Indy takes it, it's once again open. (00:42:15)
Other mistake: When they go under the coffin you see the flame of the torch in the background. How could the flame go under the petroleum with them without either setting light to the petroleum or being extinguished itself? (00:35:55)
Factual error: When Indy and his father are being chased by the German soldiers on motorbikes they can be easily identified as modern lightweight Japanese trailbikes (Honda XL500S from the '70s/'80s), not the big heavy bikes the German army used. Furthermore, the sidecar used by Indy, instead of being a BMW supplied to the Wermacht, is a Soviet copy (Dniper or Ural) produced in the 1980s, disguised to look like a BMW. (01:03:35)
Revealing mistake: When Indy is breaking through the wall in the catacombs, and he uses his shoulder as a battering ram. You can see his head actually bounce off a piece of the rock real hard as he is going through the wall. If the rock was real, I guess Indy would have a lot to cry about that night. (00:32:00)
Suggested correction: This rock is real but very old. That's why it was easy to break.
Continuity mistake: Inside the zeppelin when Indy and his father are talking at the table, notice the white handkerchief that moves all around the table. (01:13:50)
Factual error: Jehovah is spelled Iehovah in Latin. However medieval languages (Latin or vernacular) had neither official rules nor the letter 'J'. It was not until the sixteenth century that the French humanist Pierre de la Ramée proposed to use the 'J' as a separate letter distinct from the 'I'. The 'J' could therefore not have been a trap at the time the test was constructed. (01:46:20)
Suggested correction: The concept of what looks like a "J" was sometimes used when writing numbers in Roman numerals, originating sometime in the Middle Ages. While "J" did not exist as a letter at that time, what visually looked like a "J" did exist at the time the Trial was made. The purpose is to weed out those who can't spell the word of God...there's nothing implying that whoever created it meant for all the tiles to be understood as just letters.
Revealing mistake: Indy and Henry go through a tunnel to avoid the Nazi planes, but one flies into the tunnel anyway. When it goes into the tunnel, it's covered with matte lines, and it's the wrong color.
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.
Continuity mistake: While Henry and Marcus are being held inside the tank, Indiana rides in circles and baits the tank to ram into one of the cars. In a following shot when we see Vogel walking toward the window inside the tank it's a flipped shot, note everything is backwards: strap, button, armband. Then two shots later, when Vogel shouts "quick" in German it's another flipped shot, and about five shots after that again flipped. (01:29:30)
Revealing mistake: Just a small detail. Watch the tank roll over the hill with the German officer holding onto the top. When the tank hits the ground, the turret pops off. The German soldier (a clear prop dummy) maintains its grasp on the turret and is pulled off with it. The sheer force of the crash would have easily blown a human body off the tank. (01:36:30)
Continuity mistake: In the speedboat scene where Dr Schneider rescues Indy and Kazim from the boat that is chopped up by the propeller of a ship, she driving the speedboat with the steering wheel on the right-hand side. Seconds later as she drives the speedboat away, the steering wheel is on the left-hand side, obviously a flipped shot. When the speedboat slows down to allow Kazim to alight at the jetty, Indy is at the wheel which is now back on the right-hand side. (00:39:55)
Visible crew/equipment: After the Venice boat chase scene, in the shot which takes place on the boat while it is being chopped up by the propeller, look at the top of the boat (opposite where Indy is holding Kazim.) You can see a series of round-shaped set lights reflecting in the boat. (00:39:30)
Continuity mistake: When Indy is trying to hold Elsa and keep her from falling and she's trying to reach the Grail, you can see her hand coming out of her glove. In the first shot of her hand coming out, it comes almost all the way out. In the next two shots, her hand is about halfway out, then it slips out and she falls. (01:57:00)
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)
Continuity mistake: In the beginning, when Indy is fighting aboard the Coronado ship, the very first time we see Indy in this scene (before we see him get punched), he is bleeding from the right side of his mouth. Throughout the remainder of the scene, he is bleeding from the left side of his mouth. (00:11:50)
