Plot hole: In the course of the story it's said that at the time the black hole went out of control, it had a mass of "half a mountaintop of granite." But in a flashback scene Dr. Krone is shown growing the mass of the hole by feeding it large numbers of lead bricks in the laboratory. It's a little hard to believe his lab could store, or even afford, enough lead bricks to equal that much mass.
Revealing mistake: In the very first scene, which takes place in a Moroccan sheepherder's meadow, the camera makes some gentle panning motion. The mountains in the distance can be seen noticeably moving not quite in sync with the foreground. The foreground is actually in Texas (according to the director's commentary), and the mountains were added in post production.