Against the wishes of director Kurt Wimmer, the film was completely re-edited by the studio after they saw the original version which they apparently did not like; they saw it as 'too emotional' for the action film they were expecting and re-edited it so there would be more of an emphasis on the action and to cut it down to a PG-13 rating. The edition shortened the film from its original length of 120 minutes to 88 minutes. The director was quite angry about the edition, and many fans agree that it lowered the quality of the film significantly.
In the beginning, when Violet is escorted into the building, the corridor is painted in yellow and black bands which seem to form 6 roughly equilateral triangles of alternating yellow and black: the "fallout shelter" symbol. This is not, as previously stated, the logo of the Umbrella Corporation from Resident Evil. The Umbrella logo is eight red and white isosceles triangles forming an octagon.
While on the set, Kurt Wimmer asked Milla Jovovich to punch him, in order to get a feel for the intensity she was putting in her action sequences. For the next several days, Wimmer directed the film with a black eye.
Long before the release of the film, a teaser trailer and a rough cut of one of the action sequences leaked to the Internet after being shown to a small group. Kurt Wimmer requested that all clips be taken offline in order to keep the film mostly a secret until he decided to let it out of the bag. The clips were apparently all removed.
Kurt Wimmer has stated that the film was directed in such a way as to allow for an alternative theory about the story. In this theory, this the character of Six is actually Violet from the future, who comes back after a cure for hemophilia has been developed. This explains how Six has the cure and nobody else does. It also explains why Violet is so adamant about protecting a human, despite her goal in life being to kill them all (although she doesn't know Six is her from the future, she can just feel it). The theory also explains why Six often disobeys Violet and leads where they go. Being Violet from the future, Six remembers how things happened in the original timeline, and can prevent them from occurring this time around.
[muzzle flash symbol]
the muzzle flash on Violet's Uzi-like submachine resembles the biohazard symbol, similar to the way in Wimmer's previous movie Equilibrium, that John Preston's guns have muzzle flashes that resemble the Tetragrammaton symbol.