Continuity mistake: In the British Museum, when Rick and Ardeth are saving Evie, Rick gives her a .45 pistol and they start to shoot the guards, her pistol fires once and the slide locks back meaning the pistol had no ammo, but she keeps firing as if the magazine was still full. (00:39:47)
Factual error: When Brendan Fraser & his son are running to reach the pyramid before the sun hits it, the sunrise line approaches the pyramid along the ground, but the sun would naturally have hit the pyramid at the top first and worked its way down to the ground. [Some people insist on trying to correct this - think of it this way. If the sun's illuminating the ground from way up in the sky, what's keeping something higher up than the ground in darkness?] (01:34:40)
Suggested correction: Despite the additional comments this posting is wrong. The terminator line - the distinct boundary between sunlit day and dark night - moves horizontally across the surface of the earth, from east to west. It is perfectly feasible for the land behind Rick (i.e. to the east) to be in bright sunlight while the pyramid - to the west - is still in darkness. What is not feasible is anyone outrunning the terminator line, which moves at around 1500 kmh in the latitudes they are in.
Try it for yourself - get a round object, such as a basketball, a map tack and a flashlight. As you shine the flashlight on the ball you will see the equivalent of the day/night terminator line. Now stick the map tack into the ball and slowly rotate the ball with the light still shining on it. As it moves, the terminator moves and the map tack will become illuminated before the surface of the ball at the base of the tack. The light will move down from the top of the tack. The only way it would work as shown in the movie is if everything is exactly flat - with no differences in altitude above the ground. Obviously that is not the case. (Of course, if you don't want to poke holes in your basketball, you can use any combination of something round and something to stick to it.)
The original post is correct. Because of its sheer height, the top of the pyramid would receive direct sunlight first, just as a mountaintop receives sunlight before it appears on level ground.
It is perfectly possible for a mountain to be in complete darkness and the low lying land nearby to be brightly sunlit if the mountain is to the west and has not yet been reached by the terminator line. I repeat, the terminator line moves horizontally (in all practical terms) across the surface of the earth and as a result anything west of the line will be in darkness regardless of its height and will stay that way until the line reaches it.
Look, you're talking about mountains miles away beyond the terminator (so far away that they would be beyond the range of sight anyway). We are talking about a pyramid, easily the tallest thing in the immediate vicinity, in the near background, only a mile away at most. Under the physical conditions and locations present in this film, the pyramid should be illuminated top-down. Period.
Continuity mistake: When Rick is trapped in the bathroom, he finds John underwater in a bathtub full of suds. As John climbs out of the tub, his body naturally is covered in suds. However, when he and Rick jump out the window and start running away, John's body is completely suds-free. (00:30:15)
Other mistake: When Rick and Ardeth Bay save Evie from the warehouse after Imhotep is resurrected, there are four mummies chasing them when they get on the double-decker bus. Rick shoots one of the mummies and "kills" it. He shoots another one in half and goes to the top of the bus to fight another one. The top portion of the mummy that got shot in half then fights Ardeth Bay. Evie kills the mummy that got shot in half and the top part of the bus gets torn off by the bridge and kills the mummy Rick is fighting. John stops the bus and they all sign with relief. Whatever happened to the fourth mummy chasing them? (00:43:20 - 00:46:40)
Plot hole: Anubis Warriors can only be killed by being beheaded. But during the final battle, you see several are killed by simply being stabbed.
Continuity mistake: In the beginning when Brendan Fraser is looking around the tunnels he turns around to see his kid and they scream. As they are screaming they are at eye level but when a few seconds later when they are standing the kid is like 2 feet shorter then Brendan Fraser, and if you look around there is nothing for the kid to have stood on. (00:05:55)
Continuity mistake: Before Fraser and the gang reach the Oasis, the falcon is sent back to the human army that is advancing in order to stop the Anubis horde. There are literally tens of thousands of men advancing. Yet after the first battle with the Anubis warriors, the human force is decimated. Only a ragged line of warriors remains for the final charge of the Anubis warriors. But there are no human bodies or horses in the sand. (01:16:50 - 01:52:30)
Plot hole: The timeline is off. Mummy started in 1923, yes, but it wasn't until three years later in 1926 that Evie and Rick actually met. Mummy Returns takes place in 1933 - only 7 years later, but they've got an 8 year old son. At that, Rick and Evie's son was born the year before they met... (00:04:45 - 00:42:35)
Continuity mistake: In the first movie, Rick (Brendan Fraser) has a tattoo of the eye of Horus on the back of his right hand (easier to see in the theatres than on the video, but if you look closely you can see it several times throughout the film). However, in the sequel the tattoo is gone and now he has that tattoo on his forearm, which he didn't have in the first one. Considering the time period, tattoo removal wasn't possible. (01:51:25)
Continuity mistake: At the end of the movie, when Imhotep is hanging off the ledge, if you look at his arm and his hand, there isn't any pressure being put on them, almost like he's just standing behind it, with his arms resting on the ledge. (01:52:20)
Continuity mistake: During the ride on the double decker bus. Rick is fighting the mummy by punching him in the face. The mummy's tongue and face are a grey color. Right before the mummy gets killed on the low bridge we cut to his expression and his tongue is pink. (00:44:20)
Revealing mistake: In the visions of Nefertiri scene where Nefertiri is fighting Anck-su-Namun back in ancient Egypt, Evie (Nefertiri) gets knocked to the floor and when she lifts her mask up you can see on her right index finger is a band aid/plaster. Did they have plasters back in ancient times? (01:07:49)
Revealing mistake: In the British Museum after O'Connell frees Evie from being sacrificed, they both shoot at glass containers filled with alcohol and formaldehyde. Right before they explode, you can see protective masks very clearly on the guards that were standing in front of them. (00:39:51)
Continuity mistake: When Rick and Ardeth are saving Evie from the library Ardeth manages to shoot the chemicals and blow them up. When you see him shoot them from Ardeth's view Imhotep has disappeared, as he was standing next to the chemicals before they were shot. (00:38:55)
Continuity mistake: During the first battle, the Scorpion King is fighting with his sword in his right hand and his shield in the left. For one instant, they change arms. I assume the film must have been reversed. (00:01:46)
Revealing mistake: When Jonathan gets separated from Rick, Alex, and Evelyn while running, he bumps into another surviving guard and they keep running together. While they're running, if you look on the ground, you can see tire tracks left by the camera vehicle. (01:33:00)
Revealing mistake: In the scene when Rick and John are pinned down in the lavatory by machine gun fire, if you look at the stained glass window before they jump through it, it is smooth but just before they jump through it it is textured like break-away glass. (00:31:40)
Revealing mistake: During the first battle between the Medjai and the Anubis warriors there is a part when all of the Anubis warriors start to get killed off. You can see a Medjai jog across the bottom of the screen from right to left with his sword held out. He runs into an Anubis warrior at the bottom left hand side of the screen and he turns to sand. It's obvious that the guy wasn't doing anything and they just edited in a warrior and had him destroyed. You can tell that the direction for these guys was, "Just run across the screen like you're in battle." Some of the guys are real animated and jump and hack, this guy just looks like he's taking a leisurely jog. He doesn't even swing his arm. (01:47:07)
Continuity mistake: In the first big catfight between Anck-Su-Namun and Nefertiri (in Seti's throne room), look carefully when Nefertiri is knocked down the first time. Her weapons fall to the ground; however, when she bounds back to her feet, the knives have magically reappeared in her hands. (01:04:50)
Factual error: There were no jet engines outside of a few top secret military laboratories in the mid-Thirties, and there has never been a jet propelled airship ever, anywhere. Even using jet engines as auxiliary power, as this one does, the acceleration would rip the airbag to pieces.