Continuity mistake: The red-marked leader of the ARC Troopers sure goes through a rapid succession of field promotions and degradations. In Chapter III, he is addressed by Obi-Wan as a Sergeant; when Obi-Wan arrives at the Banking Clan's HQ in Chapter IX, he calls him Commander; and when Anakin returns from his duel with Asajj Ventress in Chapter XX, he is suddenly a Captain.
Continuity mistake: After Padme drags Threepio away as the attack on the city begins, Mace Windu's fighter swoops across the screen from left to right, and it rolls onto its side to show us the top of the cockpit. We see his canopy is similar to the design found in the 'Revenge of the Sith' film, being comprised of three large panels of glass. Unlike the film version (which has a small porthole behind the pilot's head), there is no glass behind Windu. But when the shot cuts to show him inside, there are three windows behind him. Seconds later, another interior view shows the three 'windows' are now solid panels.
Continuity mistake: When Count Dooku and the disguised Asajj Ventress watch the fighters in the Rattatak arena, the lodge they sit in at first seems almost level with the arena floor. Later, when Dooku floats to the arena floor after Asajj has finished all enemies, the lodge is high above the ground.
Continuity mistake: When Palpatine and his rescuers are in the descending elevator, a wide shot shows the trooper with the rocket launcher standing at the far left of the shot, in front of the hammer-headed Jedi. The shot then tightens in and suddenly this trooper is behind Palpatine, who is behind that Jedi.
Factual error: After Oro Dassyne has boasted about his fortress' defenses and the droid standung by him announces that he has spotted two Jedi approaching, Dassyne snatches the binoculars from him to take a look himself. Curiously, he holds them at a very different angle, i.e. he is not looking into the same direction the droid was looking, and still he spots the Jedi immediately.
Other mistake: In the Banking Clan's HQ, San Hill assesses the situation: "Those guns are destroying our forward positions. The Republic is breaking through!"; then the ground shakes when the giant cannon outside is blasted, and Hill flinches in surprise. But if you look closely, he flinches just before the explosion and the resulting tremor come in.