Revealing mistake: During the scene where Lara and Reiss's henchmen are fighting in the lab with the orb, look closely: the computer monitors in the background briefly flicker (as most monitors appear on camera), indicating they were shot in the background. During the close-ups, this does not occur.
Revealing mistake: When Lara and the guy race with their bikes by the Great Wall, Lara's stunt is noticeable because her face is rounder and not so angular.
Answer: As the movie sets out, that is the "Sunday school" version of the story. Within the movie, the legend is based on an artifact that not only bestowed life upon the earth but also slew all who opened it with horrible disease, gaining a reputation for containing the essences of both "good" and "evil."
Phoenix