Continuity mistake: While the runaway and the Cyborg Master are fighting in the church, there are bloody cuts on the runaway's chest that keep appearing and disappearing between shots. In addition, he also suddenly gains a cut above his eye, that conveniently enough is already covered with a band-aid he didn't have there to begin with.
Continuity mistake: When sister Ann and the runaway slave are in the train, her hair is in a ponytail with a few loose strands hanging out. She hands the slave a cookie, then leans back against the wall. Cut to a close-up of her face, and her hair looks very different, with lots more hair hanging loose down the sides of her face.
Continuity mistake: In the very beginning of the movie, Ann and Fred are walking through the a tunnel in the sewer. They reach a dead end but in the next shot, the place they are has completely changed, the dead end is just another tunnel and the light comes from another direction (all can be seen when they go down the ladder).