Continuity mistake: When O'Connell is locked out by Beni his .45's are empty and the slides are locked open on both. When he throws his pistols ahead and does a dive/somersault move, then goes for one of his pistols, the slide has closed. (00:10:10)
Visible crew/equipment: In the scene where Rick is beating up Beni in the Egyptologist's office, as Rick throws him on the desk, there is a flash of light that has no visible source, and a metallic clink can be heard off to the right. (01:17:50)
Suggested correction: If you look closely, Rick actually knocked a lamp off the table when he throws Beni on it, and it hit the ground and popped... hence the flash of light and "clink" sound. You can briefly see it in this video at about 34 seconds in, right as Beni hits the table. It's a sort-of gold color and it's right behind Rick and Beni. Https://www.youtube.com/watch?v=dL3zacTLLJQ.
Deliberate mistake: The shot of Ardeth and his companions watching Rick leave Hamunuptra at the start of the film is reused again when Rick, Evie, Jonathan and the Warden re-enter Hamunuptra, although the reused shot has a blue filter over it. Ardeth even says exactly the same line he says in the original shot, but it is subtitled differently.
Continuity mistake: Just after the bug has crawled up into the guy's head, you come back to where Rick and the others are. You see that Rick is wearing those wrist bracers. When they hear a scream they go running. In the next shot Rick does not have the bracers. (00:47:40)
Deliberate mistake: When they first enter the tomb, Evie moves a mirror which deflects light onto a load of other mirrors. You can see the beam bounce from mirror to mirror as it goes along the chain. Whilst this looks cool, the speed of light is far too quick for this to actually be noticeable as shown.
Other mistake: Evie traces the marks on the inside of the coffin lid to show how they were made. Problem is, there are five parallel marks that all line up with each other. If they were really made be fingernails, the thumb mark would have been different from the finger marks. (00:56:20)
Continuity mistake: After the scarab enters his body, Jonathan contorts his arm in pain/reaction giving a view of his palm, through which the scarab entered. But there is no visible wound, blood, or any other sign of entry for the scarab to have gotten in. Also there is no visible blood when Rick stabs Jonathan to get the scarab out.
Continuity mistake: On the boat, as Rick is checking his weaponry, he cocks his 45 and puts a magazine in. Hearing a noise, he walks over to deck cargo and pulls Benny out. He then places the 45 against Benny's chest and threatens him. The 45 is no longer cocked.
Continuity mistake: When Rick finds Beni in the office, after Beni says "I am immune", Rick slams him into a pile of boxes, sending stuff flying. Nothing is visible behind Beni's head, just a sheet of paper at neck level. Then after Rick says "immune from what?" we cut to a different angle - boxes are now piled much higher behind Beni, and there's a bit of paper resting on his hat. (01:15:00)
Continuity mistake: In the scene when they are driving through town trying to escape the mob, the car crashes, and you can see that its lights are on. When Rick helps Evie out of the car, its lights are off. A few seconds later, you can see in the background that its lights are on again. (01:27:20)
Factual error: The head of the prison is described as the "warden". This is an American term. In countries dominated by Britain, as Egypt was at the time, the head of a prison is the "governor".
Continuity mistake: Whenever a scarab crawls out of its "blue gold" shelling, it leaves the shelling behind. At the end of the film when Jonathan picks one up and the scarab crawls inside of him, he begins to scream and you can see the shell still on his hand yet in the next shot, he throws his hands up yet no shell is thrown away or even seen on the ground. (01:37:00)
Other mistake: Evie explains that if Imotep was resurrected he'd bring with him the ten plagues of Egypt. This is followed by (in no particular order) a plague of Locusts, Flies, Water running to blood, the sun being eclipsed and a plague of boils. At the plague of boils Jonathan says 'last but not least, my favourite plague - boils and sores'. How does he know this is the last plague? Aren't there supposed to be 5 more? (01:23:10)
Suggested correction: This may be taking the dialog too literally. It may be foreshadowing, in the sense of "uh, oh, they've got us now" or Jonathan may simply be expressing the fact that he's had enough plagues now and would like it to stop please. By the way, you forgot the fire raining from the sky, so technically Imhotep did six, not five.
The fact that Evie stated specifically 10 plagues, it makes no sense for Jonathan to say "last" on the 6th one, without considering it a mistake on the parts of writers, actor, or director.
Jonathan doesn't simply say "last", but rather "last but not least" - a statement that is regularly used on things the speaker knows for a fact to be, in fact, not the actual last. Taken as a sarcastic remark it makes perfect sense in the situation.
I know he said more than just "last", but that was the keyword to point out that the mistake is in fact valid. "Last but not least", weather said sarcastically or not, is never meant to be said about something that is in fact not last. It's always said to indicate the last item is not necessary the least, such as at Christmas when the last gift remains or when the last graduating student is given his or her diploma.
Also it's a possibility that off screen there was death of livestock, lice, raining frogs and death of first born children. Just want to show which we missing and it's obvious why, as in a movie raining frogs or dying livestock isn't all that threatening to the main characters and doesn't look cool. And for the movie showing first born children die is just stupid. And lice, that's just too much like flies.
Continuity mistake: In the beginning, during the initial battle sequence, there is a scene where some men on horses go up a little hill, over all these dead bodies. The body right in the middle of the shot jumps two different times when a horse runs over his legs.
Revealing mistake: When Imhotep transports Evie, Beni and himself back to Hamunaptra, Evie hears the plane and looks up. Before she states "O'Connell," you can see the letters and numbers on the side of the plane are backwards, like a mirror image - it says "B5538" backwards, which resembles "BE228" (no mirror). (01:32:15)
Visible crew/equipment: In the shot where our heroes are climbing down into the tomb for the first time you can see Brendan Fraser holding the handle of a wire which was removed digitally. This is even mentioned in the director's commentary on the DVD.
Revealing mistake: In the initial battle sequence, in one shot you can see the special effects canister from which the sand explodes up.
Continuity mistake: When the fat guy who gets the beetle in his brain runs into the wall, his shirt is untucked. The camera changes angle and it is tucked in. (00:47:50)
Continuity mistake: When the hero and heroine are kissing, you first see it from behind him looking at her face. From that viewing angle they both turn their heads to the right to kiss each other. Then we see it from behind her and in front of him, but now they are both turning they heads a little to the left.
Continuity mistake: When Rick stabs Imhotep, at the end of the movie, we can see blood on the hands of the mummy. In the next shot, however, his hands are clean and there's no blood coming off the wound. (01:51:00)
