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.
Continuity mistake: After the slave boy gets a cigarette from O'Neill, he reaches out to touch a gun, and O'Neill grabs it and scares the kid away. O'Neill 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.
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).