Continuity mistake: In the first scene when Rigel is crouching, taking pictures of the werewolves, he is holding the camera in his right hand just as he is about to jump down. However, when he is jumping, the camera angle changes and it can be seen that he is no longer holding a camera in his right hand. (00:02:10)
Revealing mistake: In the fight scene between Michael and Viktor, you can see several times where Michael's dark colored make-up has been wiped off his lips.
Continuity mistake: When Selene is chasing the Lycan in the subway and is surprised by him firing at her from behind her she turns around and gets down on her knees and fires back. When it cuts she gets down on her knees again. (00:08:25)
Revealing mistake: In the end fight scene between Viktor and the hybrid Michael, Viktor picks Michael up and throws him into a stone column. Terrible wirework then comes into play: Michael travels far too slowly towards the column for someone who was just thrown, he makes one perfect spin in the air on his way, and when he finally connects with the column, it's a delicate bounce off before the wire drops him on the ground. His legs don't even move from the "impact". (01:47:15)
Revealing mistake: After Selene jumps off the building at the beginning and lands, there is a very large upwards pull (that stays in place until the camera cuts away) in her cape near her head that is in fact the drop wire running under her cape to the harness on her back (although the wire has been edited out). (00:02:40)
Plot hole: Singe states that Viktor and Amelia are pure-blooded Vampires, and seems to agree when Viktor calls the story of the Corvinus Clan a legend. However, Evolution shows that Lucian had formed a partnership with Andreas Tanis, a Vampire who was outcast by Viktor specifically because he knew the truth of the Corvinus Clan and the origins of the Vampire and Lycan bloodlines. Given his lack of loyalty to the Vampires, there is no reason why Tanis would not have told Lucian that Viktor and Amelia are not pure-bloods, or that the legend of the Corvinus clan was entirely true. Lucian would have passed this information to Singe, as it would be vital to his work.
Continuity mistake: When Lucian goes flying over Selene's car, in the overhead shot we see that the road below him has large parts with visible concrete because there are no paving stones. But in the next shot, a close-up of Lucian landing on his feet, the road is fully paved with paving stones. (00:28:20)
Factual error: Selene's guns are apparently capable of firing 30 rounds without reloading. Considering the size of the ammunition, this is physically impossible.
Revealing mistake: When Lucian is draining blood from Michael, the tip of the syringe bends like rubber. (01:21:25)
Continuity mistake: When Michael grabs Adam's arm and Adam tells him to let go, Michael is holding Adam's arm close to his chest. When it cuts, Adam's arm has moved over to his shoulder. (00:42:30)
Revealing mistake: As Lucien reprimands the Lycans for their pit fights, of the two Lycans who were just fighting and were naked during that fight, on the taller one the top seam of his underwear/pants is visible. (00:11:10)
Continuity mistake: During the fight scene towards the end, Michael Corvin (now half lichen/half vampire) flies through the air from being hit. At this point Michael’s color is a translucent black/grey. As he flies through the air you can see that his feet are white. (02:00:35)
Audio problem: At the beginning, when Selene is hunting the Lycan though the subway tunnels, she is pressed against a wall, and she starts to look around the corner. Then suddenly a subway train passes by. Shouldn't we have been able to hear it? (00:08:10)
Continuity mistake: At the shooting range, Selene is shown firing a black USP without a compensator. It then cuts to an over the shoulder shot, and she is now firing a two-tone USP Match (which she supposedly receives from Kahn to test out a few seconds later). It then cuts to a frontal shot of her, and she is once again using the same black USP. She never stopped firing, so she couldn't have switched guns.
Continuity mistake: As Viktor's tomb is opening there is a shot from above showing Selene looking down the opening tomb. Watch the placement of her feet. In the next shot, her feet have moved closer to the opening. (00:44:40)
Continuity mistake: When Erika discovers that Michael has been bitten - just before he leaps out of the window and escapes the vampires' mansion - there is a patch of blood above Michael's eye that disappears. (00:36:55)
Revealing mistake: The edges of Selene's bright blue contact lenses are VERY visible in the scene near the end where she is on the ground, talking to Viktor. (01:44:30)
Continuity mistake: Selene shot Singe in the right shoulder, but when she brings him in front of Viktor, the injury is in the left shoulder.
Continuity mistake: Whenever Raze transforms into his wolf form he takes off his jacket, but when he leads the other werewolves to assassinate the council members and to drain Amelia of her blood he all of a sudden has his jacket on. He couldn't have stored it on the train.
Continuity mistake: Lucian has just walked into the werewolf fight right after the opening subway chase scene. His face is faintly lit in medium shots and completely in the shadows in closeups. (00:11:00)
Chosen answer: In most of the shots, Lucien takes his coat off when he changes to wolf form, and the blade would be attatched to a mechanism in him coat. Also, the film gives us an example of the blade hurting a vampire: bloodloss. And that kind of weapon could do some serious damage, and as it probably wouldn't kill the vampires, it would almost definitely slow them down.