Continuity mistake: Indy slams a pole against the big X on the floor and produces a hole. When the angle changes the shape of the hole is completely different.
Revealing mistake: When the tank shoots-up the jeep the interior is revealed to be empty and such a prop.
Continuity mistake: While in the zeppelin, the German officer extends his baton and lowers Dr. Jones's newspaper, wrinkling it. From the opposite angle, the newspaper is still raised and the officer repeats the previous movements, though this time he doesn't wrinkle the newspaper.
Continuity mistake: Hitler walks surrounded by a huge crowd ahead holding Nazi pennants. When Indy bumps into Hitler, half a second later, the pennants on the left have disappeared.
Continuity mistake: Dr. Jones hugs his son and walks 20 meters away. When he turns around to address him, he is barely 5 meters away.
Continuity mistake: When a jeep gets stuck to the tank's cannon, the type of jeep, its position and the damage done changes between the first and second shot (watch how the smashed windows fix themselves, for example).
Continuity mistake: The position of the stone that Indy places to block the cannon changes between shots.
Continuity mistake: In front of the main tribune there's a pile of burning books. First the fire is just atop, a frame later the whole pile is burning.
Continuity mistake: After Indy and Elsa exit the catacombs through a sewer and start to run away, a woman in pink turns her head to watch them leave and then turns around to see Kazim's men run after the couple. A frame later, from a new angle, the woman's head is turned 45° facing downwards.
Continuity mistake: Sallah rescues Dr. Jones from the tank and stops by the cliff. On the next wide angle he's nowhere around.
Continuity mistake: Indy stops his sidecar at a crossroad, meters ahead of a house. When the angle changes he is now several meters behind.
Continuity mistake: During the crashes by the border control the road keeps swapping from sunny to shadowy back and forth in less than 3 seconds.
Continuity mistake: When Indy jumps on Kazim's boat, Elsa's boat is inches away from Kazim's, but a shot later she has managed to appear somewhere else with no boats around.
Continuity mistake: When Marcus watches the carbon copy of the shield, his ice-bag is on the table, but when the angle changes he has it next to his head and seconds later he puts it on the table. Also, the ashtray moves backwards between shots.
Continuity mistake: On the tank, Indy is punched and the gun falls inside. His hat also falls off, but a shot later it's back on, perfectly tucked in.
Audio problem: When the temple floor cracks, Indy holds Elsa from falling into the void and she gives a very loud cry, but her mouth is closed.
Continuity mistake: After Dr. Jones fires at the jeep two soldiers fly towards the tank, but when the angle changes they're falling away from the tank.
Continuity mistake: Inside the temple, when Indy is at the cliff, in the close-ups the rocks next to him are round shaped, but in the wide angle they are straight and stripped.
Continuity mistake: When about to walk on air in the temple, Indy says, "No one could jump this". In the close-ups his hands are spread apart, but in the wide angle they are grabbing the diary.
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