Vlix has three nostrils, but the one in the middle disappears or is not colored in for few frames during several of his close-ups.
Near the end, when Jord says 'An express run right to it', his red sleeve turns blue for a few frames.
After Thall uses the lightsaber for the first time, he holds still in a heroic Jedi-like pose. When he deactivates it, he is suddenly standing next to the White Witch again, which he could not have been without walking a few steps backward.
When Thall uses a lightsaber to break open a large door, he is pictured standing on top of two stalagmites instead of behind them.
Right at the beginning when the A-wings fly by they emit the characteristic sound of the TIE-fighter.
After Threepio gives Thall and Kea the odds, when Kea says 'Not much worse', she blinks, but her eyes completely disappear for a couple of frames.