Continuity mistake: By the border, when the German soldier's been knocked off by Indy and his bike rides alone, he suddenly disappears from the side of the road. (01:02:10)
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: 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)
Continuity mistake: When Indy and his father are being pursued by German soldiers on bikes, right after they break through the barrier, the barrier guard comes out of his post and waves the pursuing German soldiers to slow down in the background. In the next shot he's no longer there, and the barrier's quite far away, then in the following shot he's back, and Indy's not so far from the barrier again. (01:04:35)
Continuity mistake: The remaining Nazi biker passes among his fallen compatriots following Indy. The latter looks over his shoulder at the biker. In the next shot, the background behind the Nazi is totally different (the bodies, the motorbikes and the hut have disappeared). (01:04:53)
Factual error: When Hitler signs the Grail Diary, in the screen and VHS release he signs Adolph, not Adolf. This mistake was corrected in the DVD release. (01:07:35)
Factual error: When Indy and his Dad are in Berlin, there is a big book burning going on. But the only book burning that was held in Berlin was May 10th in 1933 - 5 years before the Joneses visit it in search for the Holy Grail. (01:07:50)
Factual error: When Indy is wearing the uniform of a German Artillery Officer, he is wearing the ribbon of the 1939 Iron Cross 2nd class in his buttonhole. The movie takes place in 1938. (01:09:05)
Continuity mistake: When Indy meets Hitler, there is a shot over Indy's shoulder that shows his lips are slightly parted (relaxed). Cut to Indy's face and he closes his mouth tightly. In the very next shot, with no elapsed time, we see from Indy's shoulder again that Indy's mouth is relaxed as before. (01:10:15)
Factual error: When Hitler signs the diary, he writes in a modern way of writing. But in the late 30s there was a different style of writing called "Suetterlin". The letters looked quite different from nowadays. (01:10:25)
Revealing mistake: Just after Vogel is thrown out of the blimp, in the shot of him shouting towards it whilst it is taking off, it is apparent that the sky and blimp shown in the background behind him are a projection. (01:13:20)
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)
Other mistake: On the zeppelin, Indy's dad says, "You left just when you were becoming interesting..." Harrison Ford is mouthing Sean Connery's lines. (01:14:50)
Continuity mistake: When the zeppelin is shown turning around, the biplane that the Joneses are about to escape in is nowhere to be seen. (01:16:10)
Revealing mistake: The biplane sequence is obviously filmed in a studio close up. Despite the fact that they are miles high and swooping around at high speeds, neither Indy's hat, nor his Father's, blow off or even flap in the wind. (01:16:55)
Factual error: German Fighters shown in the film are in fact Pilatus P-2 (Swiss-made aircraft built after World War II). The appropriate fighter of the period would be the Messerschmitt 109. (01:17:00)
Factual error: When Indiana's father uses the plane's gun, he shoots out the tail. This was not actually possible, as the planes had a safety mechanism to stop people doing this. In fact we can see that the Lewis gun he is using is mounted on a Scarff ring, which prevented the trigger of the gun being activated when the barrel was pointed at the aircraft's tail surfaces. (01:17:40)
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)
Continuity mistake: In the wide shot of the Nazi convoy, Colonel Vogel can be seen walking alongside a troop truck. In the next shot, he is no longer there. A few seconds later, the colonel appears from the right side of the screen. (01:23:49)
Continuity mistake: When Indy and gang are racing the Nazis to the canyon of the Crescent Moon, Indy looks at the Nazi convoy with binoculars. Close-ups of Indy show the sun is clearly behind him, and the binoculars are in his shadow. But then a glare from the lens alerts the Nazis to their presence. (01:24:25)
Suggested correction: It is not clear that the glare is coming from the binoculars rather than the car behind them (after all, the Nazis target the car with the tank).
They see a glare rather than a car. But anyway, regardless, the problem remains that the sun is behind the car too.
