
Continuity mistake: During the temple quake sequence towards the end of the film, Elsa fails to maintain her grip on the rising earth and falls onto tilted ground, sliding towards the chasm. At this point, Sallah is kneeling on the ground, but in the very next shot, he is now grabbing hold of Henry.
Continuity mistake: When the Hatay soldier is decapitated in an attempt to navigate the temple's defences, his head rolls along the ground and Elsa turns her head around and looks over her shoulder. In the next shot, she has now turned her full body around, and in the shot after that, she is looking over her shoulder again.
Continuity mistake: When Elsa's hand slips from its glove whilst Indy is holding on to her, Elsa falls and she is holding the glove in her right hand, but when she falls into the chasm, the glove has gone.
Continuity mistake: When Elsa is looking out over the Canyon of the Crescent Moon, the sun is low - it is close to sunset. However when Indy is riding through the very narrow canyon, the sunlight reaches the bottom. It is not the same time of day (or later the same day).
Continuity mistake: When Senior is rescued from the tank with a whip around his ankle, the whip dissappears a split second later, when he is being mounted on the horse.
Continuity mistake: When Indy is rescuing his father from Brunwald castle, he uses his bullwhip to smash through the window of the room his father is kept in...but in the time it took to jump into the room and get smashed over the head by his father, the bullwhip he used would have lost lots of its momentum and it wouldn't be waiting for him to grab it and use it later on the movie. (00:47:40)

Continuity mistake: When they are first looking over the cliff at the tank, Sean Connery's beard is quite full, and in a shot moments later, still looking off the cliff, it has been trimmed. This is due to the fact that this scene was filmed after principal photography had ended.
Continuity mistake: During the big chase scene leading up to the three challenges, Indy uses his gun and begins to takes the high road on his horse. Harrison Ford couldn't seem to find the holster for his gun, so you can see his holding the gun by his side until the scene changes. (01:31:15)
Continuity mistake: The back of the boat gets chewed up by the prop in the same place twice.
Continuity mistake: After Indy exits through the sewer with his hair all wet, he escapes Kazim's men. When he turns around a block his hair is nicely combed and loose, instead of sticky. Not too plausible when you're running for your life and your head is soaked in petrol.
Continuity mistake: The distance between Indy's boat and the big red and white ship keeps increasing and decreasing randomly.
Continuity mistake: In the zeppelin, after Indy says "no ticket", everyone searches for their tickets and waves it at Indy. When the angle changes, a frame later, the people are searching for their tickets, no one is showing one.
Continuity mistake: The crater Indy's car falls into becomes bigger and way deeper between the first and second shot.
Continuity mistake: When the driver of the tank is shot and he changes the direction of where the tank is going, Indiana gets up, with his strap still stuck on the nozzle. However, in the next shot, he's become clear of being stuck. There's no way he could have gotten his strap undone so quickly.
Continuity mistake: Near the end, in the "Leap of Faith" scene, Jones steps off the edge of the abyss and discovers an ingeniously-camouflaged stone bridge. The camera pans to show the camouflage effect from another angle, and it's obvious that the stone bridge is only about one foot thick from one end to the other. Relieved, Jones scampers across to the other side, and the camera cuts again to show that the bridge is now a full three feet thick.
Continuity mistake: Before the propeller chops the boat, Elsa leaves and looks at Indy. Right then, the camera is reflected on her boat's windshield.
Continuity mistake: When Indy is at the Lion's Head reading from the diary, he has the diary in his right hand and moves his right hand away from him towards the rock wall. The next shot is a long shot and shows Indy holding the diary with both hands in front of him by his midsection.
Continuity mistake: Indy jumps on top of the tank from a slightly elevated path that's located next to the road where the tank is going. However, when Vogel emerges from the tank's interior, the camera focuses on the landscape behind the tank, and the path from where Indy jumped is gone. (01:31:25)
Continuity mistake: When Indy first shows up in the uniform inside the blimp, he turns to squarely face a man sitting in a chair near the wall. When it cuts to the next shot of the German, he's turned ninety degrees to the right. Too fast between shots.

Continuity mistake: During the fight on the Coronado's deck, Panama Hat is climbing the ladder with his back to the camera. In the next shot, when he says, 'Grab him, he's getting away!', he faces the camera. (00:13:21)
Answer: The implication is that disaster would follow them outside of the cave as well. It wouldn't make much sense if you could simply outrun the disaster.
BaconIsMyBFF
"Followed by disaster" is a kind of curse, a thing not common in Christianity. It doesn't make much sense anyhow. A seal is just a dot - OK, so let's at least grant that the seal represents a circle that the grail has to stay in. Who decided where those borders are? The grail was taken there during the first crusade. That was closer to 1938 than it was to 33 AD. The three knights could move the grail about then. Why not afterwards? The knights could have built the traps. But the borders could only have been set by god, in an unusually late and completely atypical miracle.
Spiny Norman
There are several examples of curses in the Christian Bible: Lot's wife is turned into a pillar of salt for looking back at Sodom, the plagues visited upon Egypt, Adam and Eve are cursed for eating fruit from the tree of knowledge, etc. The knights did not move the grail around after finding it, they stayed in the temple for 150 years and then two left leaving the third behind. The great seal and it's restriction was already in place when the knights got there.
BaconIsMyBFF
Where in the movie is that stated? I interpreted the knight's story as them having made that place. Looks like it isn't actually specified. But if God made it, then I submit that he would have used Greek, not Latin, for the stepping stones. (All of those curses are from the old testament. The book where god kills firstborn children as long as they're Egyptian. Grail is by definition new testament where you turn the other cheek. There simply are no curses in the gospel, that's just not how Jesus rolled).
Spiny Norman
The tests were made by the knights, but the seal had God's power in it. Just like the cup.
lionhead
It's still a bit dodgy. What if you take a shovel and dig yourself a back door? Basically this film really excels at stuff that makes no sense but helps the storytelling, or to be precise, creates dramatic effects.
Spiny Norman
Every fictional story is like that in some way. That's why it's called fictional. It's just a story.
lionhead
Not a particularly convincing argument, "stuff happens for no reason all the time", if I may say so. Why is this website even here then? The fact is that some stories are more coherent than others. (♫ "In olden days, a hole in the plot, would seem to matter, quite a lot. Now heaven knows, anything goes..." ♫);).
Spiny Norman
It's the difference in what story they want told. Is it a fairy tale or based on actual events? A huge difference in plausibility between the two. The site is there to look at mistakes, not how believable the story is.
lionhead
It is not set in another universe so plausibility isn't somehow suspended. Maybe take a look at the categories recognised by this website. Plot holes, factual errors, even stupidity. (They? Who are they?).
Spiny Norman
It is set in a fictional universe because it's not a true story. With "they" I mean the writers/director. Mistakes in a plot (plot holes) have nothing to do with how believable the story is. As long as it's plausible, it's not a mistake.
lionhead
Pretty sure it's the same universe, just with some added characters/events. What about the total lack of spaceships or orcs or talking animals for example? The seal business is not a mistake YET, but it's very dodgy because no-one knows how it works or why. Like all Indys "trapped" secret places, it's (among other things) unclear who resets the traps for the next visitor. We can't brush it ALL off as "the hand of god" every time.
Spiny Norman
Huge amounts of stuff in films isn't exhaustively explained. Doesn't mean there isn't an explanation that's perfectly believable. There's zero evidence either way to say how "followed by disaster" would manifest, and just because there's not a thorough explanation doesn't mean that it's "dodgy", and it's not worth bickering about either, because there's no concrete answer either way.
Jon Sandys ★
OK but I would like to note that not everyone who offers creative explanations has recently seen the movie; some people just invent their own. E.g. "followed by disaster" is not an actual explanation from the movie, it was just one of the suggestions made here and only here. Or the ones on my own question below. All I'm saying is, it's very hard to tell what the "rules" / "logic" of this place are supposed to be, so I understand what the OP was driving at.
Spiny Norman