Continuity mistake: When Obi-Wan and Count Dooku are duelling, the background behind them is inconsistent between shots. They are closer to the walls in the close-ups than in the wide shots, and sometimes the background itself changes between shots. For example, when Dooku says, "Master Kenobi, you disappoint me", there's a wall behind him, but in the previous shot, the opening of the hangar could be seen behind him. (02:00:25)
Continuity mistake: When Anakin and Obi-Wan are talking while Padmé is sleeping, as Anakin says, "It was her idea," his body is turned in a different direction from the previous shot. In the following shot, he is standing in the same position as the first shot, and Obi-Wan has turned in a different direction as well. (00:10:55)
Continuity mistake: In the arena, when Obi-Wan is trying to defend himself with a spear against the acklay, in the wide shot where it rears, he is holding the middle of the spear, but in the next shot, he is holding it higher up. (01:44:20)
Continuity mistake: In the first shot of the morning scene at the lake retreat (after Anakin's nightmare about his mother), on the extreme left of the screen, you can see the shadow of Padmé being cast on the open door to the balcony. In the next shot, her shadow is cast on the door again as she walks out the door. (00:56:55)
Revealing mistake: When Obi-Wan is cut by Dooku's lightsaber and falls, you see one of the wounds (the one on his arm) glowing and then suddenly seem to shrink and disappear, though not totally. This is because it is computer generated and didn't match up exactly with the actor portraying Obi-Wan. Hard to catch, but it is there.
Other mistake: After Jango Fett is kicked over the platform edge, he digs his forearm claw into the surface while he slides down towards the ocean. But the claw leaves no marks. Do not confuse this with the wire that locks Jango and Obi-Wan together. (00:49:45)
Continuity mistake: When Yoda and Mace listen to the Senate voting Palpatine emergency powers, Yoda starts on the top ledge nearest the Senate chamber. When the shot changes he has moved down onto a different ledge which wasn't there before. (01:29:45)
Continuity mistake: When Jango Fett shoots the Jedi that jumped up onto the platform off you see he has only one Westar 34 Pistol. But when he flies into the stadium to kill Mace Windu he has both pistols and then only one again.
Continuity mistake: When Obi-Wan and Anakin enter the nightclub, in the first shot, Anakin is walking behind Obi-Wan, to Obi-Wan's left. In the next shot, Anakin is directly behind him. There body positions differ in consecutive shots as well. (00:21:10)
Continuity mistake: When Obi-Wan begins to spin around as Zam Wessel tries to shoot him in the back, his drink is standing in front of a blue cup. But right before the next shot ends, it is standing on the right side of the cup. (00:22:45)
Continuity mistake: In the close-up of Mace Windu after he beheads Jango Fett, his under tunic is reversed. It is overlaying to his left instead of his right. (01:48:45)