Visible crew/equipment: The demolition crew can be seen on the driver's side window when Sonny Chiba and Brigitte Nielson's characters are fleeing the scene of a blown up car. The shot has Robert Davi's character chasing after them and then hearing the explosion behind him. You can see a crew person sitting and about four others kneeling, trying to evade cameras. This happens in scene 6 at 52.01 minutes into the movie. (00:52:00)
Other mistake: In the exterior shot of the Grandeur Hotel, it's a poorly made building prop and its name is misspelled "GRANEDUR." (00:18:00)
Continuity mistake: After Racine is wheeled out of the hotel on a stretcher, the uniformed police officers hand their inspector an evidence bag with the weapon used on Racine, a throwing star coated in poison. The inspector looks at it, then returns it with orders to take it to the laboratory to determine the poison. However, when we see Racine on the operating table, the star is shown, lying in a puddle of blood on the operating table, as if the doctors just now had pulled it out of him.
Continuity mistake: Alex's hands are bloody after her hunt then they're clean then bloody before becoming clean again.
Continuity mistake: The Black Scorpion's boots constantly change from heeled to flats.
Continuity mistake: When the cruise ship is overrun by pirates, one of them being pursued by Indy jumps down the stairs fine, but when Indy does it he fails and his hat comes off to the left of the staircase far from his reach. When the shot changes its back on his head.
Factual error: The cap badge worn by Captain Halliday of the RAMC is the Queen's crown version, which didn't come in to use until the 1950's. It is also made of brass, when it should be in a bronzed finish for officers.
Character mistake: When Bonnie cuffs her first arrest she mistakenly cuffs the guy in front instead of cuffing his hands behind his back.
Revealing mistake: When Dwight is falling down the stairs, you can easily tell that it's a (much older) stuntman.