Continuity mistake: When Obiwan and Anakin are fighting on the narrow walkway, lava splashes over it and causes that portion of the building to fall into the magma river. As it is falling, there is a significant amount of lava on the severed end of the walkway, which ends up as the "top" of the tower once floating on the river. For the rest of the scene this lava is gone, and none is shown falling on or by Obi-Wan and Anakin as they scramble along the side of the tower. (01:55:45)
Continuity mistake: When Obi-Wan and Anakin are fighting on the table in the control centre, they are standing/crouching in a different position from the previous shot after every time they kick each other. For example, when Obi-Wan kicks Anakin for the second time, as the shot ends, both of his feet are on the table, but in the next shot, one of his feet are up again.
Continuity mistake: After Anakin has been turned down as a Master in the council, he is walking with Obi-Wan. While they are walking you can count them passing at least five windows. When it cuts to Obi-Wan saying "Anakin, I'm on your side, I didn't want to put you in this situation", you can see, by looking at the sun shining through the windows, that they have only passed three windows. (00:36:45)
Continuity mistake: During Anakin and Padmé's conversation on Mustafar, in the first shot, they are standing near some sort of container. They continue to stand in the same place in the following shots. When Anakin sees Obi-Wan and becomes furious, both of them take several steps away from the container, but when Anakin says, "You brought him here to kill me.", they are standing near it again. In the following shots, it is nowhere to be seen. (01:39:35 - 01:41:55)
Continuity mistake: In the scene where Luke and Leia are born, the blankets under the babies are arranged differently between several shots.
Continuity mistake: In the scene where the twins are born, there are two shots where Padmé is stroking her son's (Luke) cheek. As the second shot ends, she's still stroking his cheek, but in the next shot, she is no longer touching him. (02:00:45)
Continuity mistake: When Padmé is brushing her hair on the balcony, her position changes between the second and the third shot, seen, for example, from the pattern on the floor. Her hairbrush and her arms change position between the first three shots too. (00:28:15)
Continuity mistake: After discussing whether Anakin is the chosen one or not, the ship Yoda, Obi-Wan and Windu are flying on goes in for landing. When it goes down there is no trace of clones on the ground where it is about to land. When it cuts several clones awaits them. Also two huge vehicles suddenly appears on the ground. (00:39:20)