Deliberate mistake: The 'NNN' news program shows a picture of some animal crackers in Frank's stomach. The problem is, they are still all in one piece and are pretty big. I don't think Frank would swallow them whole.
Continuity mistake: When Drix freezes the witness from the ship, he says it will take a few days to wear off. Not even a day later it wears off and the witness is back to normal and runs off only to be frozen again later.
Trivia: Thrax is like Morpheous from the Matrix trilogy. His black coat, black glasses and he is even voiced by Laurence Fishburne. In his end fight with Osmosis there is a very clear Matrix reference (the bullettime effect).