Visible crew/equipment: Throughout the movie, in the shots of the guys on the alien planet, the white reflector screens and film crew's reflections are visible in their sunglasses. (00:40:20)
Factual error: The military ranks for everyone but O'Neil are wrong. O'Neil is a Colonel (Full bird), Kawalsky is wearing the insignia of a Lt Colonel, but is referred to by O'Neil simply as Lt., when he should be called Colonel. All the others are wearing enlisted stripes (Ferretti - TSgt, but is credited as Lieutenant Ferretti), the others are also credited as "Lieutenant", but wearing enlisted stripes.
Audio problem: Right after Jackson has been dragged through the desert by the creature, it wakes him up and he says, "Get away from me," but his mouth never moves. (00:40:30)
Revealing mistake: In the scene where O'Neil is fighting Ra's bodyguard, the bodyguard uses claws and hits O'Neil's back, tearing his shirt and wounding him. But you can see Kurt's "wounds" and torn shirt right before he's hit by the bodyguard (a scene after Ra's bodyguard's claws are shown). (01:49:10)
Factual error: When they first power-up the Stargate in the military facility (using Jackson's decryption), the thing surges to life, and electrical sparks spray out of overloaded connections all around the control room. This could only happen if there were no fuses or electrical breakers in the military's control system, which is a ridiculous notion for such advanced military technology. In real life, a powerful overload situation would instantly burn out fuses and trip breakers and the whole system would simply go dead (there would be no sparks). Showers of sparks are a common error in many science fiction and space fantasy films dating back many decades.
Suggested correction: If there would be breakers and fuses then yes, the system would simply go dead and then they would have nothing. They intentionally let the system nearly overload because without power they wouldn't be able to finish the sequence.
No, that's not the way sophisticated (and expensive) electronic technology works. If you have sparks spraying out of electrical connectors, that means you're melting down millions and millions of dollars of hardware. No technician or electrician or even a first-year auto mechanic would intentionally design and hardwire an electrical system without fuses and/or breakers.
They're dealing with Ancient technology. It's quiet possible that such an advanced piece of technology as a Stargate could cause powerful arcs of electricity along lines separated even by tripped breakers.
Ancient technology does not override electrical physics. Modern electrical equipment is protected with fuses and breakers for a reason. If the Stargate technology overrode the parameters of the modern equipment, it would melt down the modern components being protected by the fuses and breakers. Either way, the whole system would shut down.
Continuity mistake: When Jackson is in the meeting about the symbols, he circles the seventh symbol with a blue marker. In the next shot, look close and you can see that the blue circle around the symbol is gone. (00:18:20)
Continuity mistake: There is no necklace on Catherine's neck when she greets Jackson in the room with the cover stones (00:13:39). After they have shaken their hands, the necklace appears on her neck suddenly. Then it disappears again. Also, after Catherine has given the necklace to Jackson for bringing him luck before his departure, the necklace appears on her neck again when she is in the control room during their departure.
Visible crew/equipment: During the final revolt against Ra and his warriors, you are able to see that Ra's warriors are swinging rubber staffs as they fight the indigenous people.
Continuity mistake: When Jackson makes his presentation, the way the hieroglyphics are drawn changes between shots. (00:06:00)
Other mistake: When Jackson and O'Neil are captured and taken before Ra, the guards hit their knees with their staff weapons to make them kneel. Jackson's guard does it right, but O'Neil's misses him completely.
Visible crew/equipment: When Ra's death gliders are sent out to attack the city of the native people, you can see wires guiding the glider models as they swoop toward the camera. (01:20:20)
Continuity mistake: Ra's soldier gets squished twice by the ring transporter. (01:47:00)
Continuity mistake: Just before Ferretti throws Dr. Jackson's suitcase his left hand goes from the handle to the side, but then the shot changes and his hand is back on the handle and moves when he throws the suitcase. (00:37:50)
Other mistake: When the team are headed to Ra's pyramid dressed like Egyptians, the door starts to close with about half a metre left. After another shot elsewhere, when it faces the door again it has more than half a metre until it hits the ground.
Continuity mistake: After the slave boy gets a cigarette from O'Neil, he reaches out to touch a gun, and O'Neil grabs it and scares the kid away. O'Neil is then holding the gun with the barrel pointing towards the door, but as the angle changes he is suddenly holding it at a different angle, pointing down to his right and away from the door. (01:05:30)
Continuity mistake: When O'Neill, Jackson, and Sha'uri have just entered the Stargate chamber, O'Neill throws aside his staff weapon and starts working on the bomb. Later, during the fight between O'Neill and the guard, an overhead shot shows that the staff weapon is no longer there.
Revealing mistake: When the crew is transported to the distant planet, there are three moons. They are all the same shot of our moon (the craters are the same), but each moon is turned differently than the other two. (00:33:15)
Continuity mistake: When the men are in the pit of water the man who says "Colonel it's us", his dog-tags change from on his chest to back several times between shots.
Continuity mistake: The bomb's countdown starts faster than a second between numbers change, then eventually gets to about 1 second/change, then goes faster, etc. Its speed keeps changing from shot to shot. Also, the numbers are inconsistent and don't match the time passed between shots of the same scene (i.e. one second later, the countdown can be 5 numbers down).
Factual error: When the USAF car arrives to speak to O'Neil, the car has a GSA (Government Services Administration) license plate on the front. As you see the door open, the printing states an Air Force Registration Number, meaning this vehicle does not require a GSA tag and should have a license plate with the letters USAF.