Continuity mistake: Whenever Amon is on screen with his mask, the design of the mouth keeps changing: sometimes there are circles on the end of it, and sometimes there is a small angle pointing up. This can be spotted, for instance, when he is talking at The Revelation.
Continuity mistake: General Iroh attacks a squadron of five combat planes belonging to Amon. He downs two immediately. One fires back and ascends. At this time, the face of the pilot is shown. The other two descend. Iroh follows and destroys them. At this time, the ascending plane drops bombs. Again the face of the pilot is shown, but the pilot is a completely different one. The first time, he has a taller face, thick eyebrows, a pair of round and brown-tinted goggles and no mustache. The second time, the face is rounder, the eyebrows are thinner, the goggles are rectangular and pale, and there is a mustache.