Continuity mistake: Just after the doctor started the post mortem on that little girl, the front of his gown is covered with blood. Yet, a few seconds later, after the two other guys appeared, his gown looks better, with less blood. And during the whole post mortem scene, the blood spot actually changes its size a few times. (00:17:55 - 00:19:55)
Trivia: The plot of the movie is a combination of two spec scripts written for the film - one was by David Twohy (Riddick) who wrote a script set on a prison planet, and another by Vincent Ward, set on a monastery planet with the same characters and basic plot. Despite this, neither received credit for the screenplay (Although Ward received story credit).