Continuity mistake: When Indy and Helena find the antikythera in Archimedes' tomb, it's covered in dust and no features are visible. When Indy reaches for it, it's just slightly dusty.
Continuity mistake: The first post-credits scene is a total editing mess: Shazam blows up the second bottle. Then shoots a second time and the bottle magically reappears and he blows it up again. Shot changes and the first broken bottle has swapped sides with the beer bottle.
Revealing mistake: Just after Dante says, "There he is, the man of the hour. Roman," we see the bomb crash into 3 vehicles, with the middle one being a blue car. In the first shot, we see the blue car get damaged. In the second shot, we see the blue car is undamaged before it gets damaged again. (00:32:20)
Continuity mistake: During the Venice scenes, Ethan's hair length is always the same, except for scene number 1 where he and the team are on a boat arriving in Venice, and scene number 3 where he and Ilsa are on a balcony. In both these scenes, his hair is very short.
Continuity mistake: When the movie begins, the way the barista holds his notepad changes between shots. (00:01:07)
Continuity mistake: When Miguel is with the pedophile, he is given bread (or something similar) to eat. Shot changes, and the bread is suddenly bitten. The bread's length keeps changing several times between shots.
Continuity mistake: When the Mafia boss dies, he falls next to a fruit stall. A crate falls next to his head, and fruit falls on the floor. When the shot changes, the crate has moved away, and the fruit has vanished.