Continuity mistake: When the first laser passes through it hits the one guy in the wrist, however we see him on the floor missing half of his fingers and hand instead. (00:31:30)
Other mistake: In the laser room everyone is lay on the floor to avoid the first laser. However in a shot from behind Alice you can see that someone is stood by the door in the corridor. (00:32:00)
Continuity mistake: When the Lasers have finished killing everyone, the EMP equipment is next to the glass wall. When Alice walks over and looks in to the corridor, it's moved. (00:32:20)
Continuity mistake: When Kaplan is walking through the corridor to get the EMP and head into the Red Queen's chamber, Medic's legs are together. When we see all the power shutting off, her position has changed and now her legs are apart. (00:32:40 - 00:35:50)
Continuity mistake: When Kaplan tells Alice not to listen to the Queen he is carrying the equipment by his right shoulder. When it cuts it has suddenly moved over to his left shoulder. (00:34:45)
Visible crew/equipment: When JD shoots the zombie female in her leg you can see the square outline of the pack behind her leg that 'explodes' and makes the hole in her pants. (00:38:10)
Revealing mistake: On the DVD commentary, the director says that he only had a handful of the experiment cubes in Dining Hall B and used cardboard cutouts for all the others. This is most obvious when Rain is walking through the hall alone to check on the first zombie: the cubes in the distance don't match the rigid rows of the ones in the foreground. (00:38:20)
Audio problem: When Matt is trying to reach the keys while kicking the zombie it cuts to Chad running against Spence who's standing by the locked door. When Chad is running you can see Rain in the background firing shots but you can't hear the shots. (00:42:15)
Revealing mistake: When the group is being attacked in dining hall B, they are trying to get the doors open. J.D. is firing at two zombies and turns away to open the doors himself because Kaplan keeps forgetting the code. If you look closely, one of the zombies reacts a second late from being shot down. (00:44:40)
Continuity mistake: When Alice enters the kennel where the zombie dogs belonged to she passes a blue trolley on her left side. When it cuts from inside the room where we watch her through the window walking, she passes the same trolley again. (00:46:05)
Continuity mistake: When Alice escapes the first zombie dog and locks herself in the room, a zombie approaches her and she kicks him down. When the zombie falls you can see his tie is partially outside of his suit. When it cuts to Alice reaching for his gun, the tie is tucked inside his suit. (00:47:20)
Other mistake: When we see the numbers for the coded entry to Alice's weapon, the order of the numbers is 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 0 - 9. The 9 and 0 are the wrong way round. (00:47:40)
Continuity mistake: When the zombie dog jumps through the window Alice makes a run through the metal door and you can see the door is clean. When it cuts there is lots of blood on the door even before the zombie dog jumps on it. (00:47:45)
Continuity mistake: When Spencer is looking through the desks, a zombie startles him by banging on the glass window. When the zombie does this, his left hand is high up on the glass. The shot changes, and now his hand is a lot lower on the glass and not entirely flush against the glass like it was previously. (00:48:00)
Factual error: When Alice has the pistol she got from the zombie she took out, she uses it to do away with the zombie dogs. As she fires the last of the rounds, the camera looks down to follow the fall of the casing. As it falls, it's on a slight tilt, about 5°. Physics says that it will bounce and tumble on the floor after it hits, then come to rest. Instead, when it hits, it immediately goes to a rest position with little movement. (00:48:20)
Audio problem: Near the middle. When Matt is searching through the office room where his sister Lisa worked, you can hear his shoes clicking as if he is on a hard surface floor, but the floor is covered in carpet throughout the office. (00:49:00)
Revealing mistake: In the scene where Milla Jovovich shoots the dogs with the 9mm Beretta she obtained from the dead security guard, a closeup of the gun is shown. Watch the cycling of the slide and you will notice that the ends of the bullets are crimped, indicating the use of blanks. (00:49:55)
Continuity mistake: When Matt is at Lisa's desk he looks through some papers, he is looking at a paper which has black squares on it. Then he puts the paper down and looks at another paper. When it cuts to him noticing Lisa approaching he is now holding the paper with the black squares again. (00:50:20)
Continuity mistake: When zombie Lisa lies dead on the floor her hair and the papers she lies on change position between the shots. (00:50:55)
Continuity mistake: When Alice and Matt run to meet up with Spencer, Kaplen, and Rain, Alice screams "Don't shoot!" and Spencer, Matt, and Alice try to close the door from the zombies. A zombie then grabs the inner part of Spencer's arm, then a shot moves showing the zombie holding onto Spencer's arm from the bottom, then back to the inner part. (00:55:45)
Answer: Actually the T-Virus was originally meant as a cure for a genetic disorder that Dr. Ashford and James Marcus daughters suffered from. The reanimation was a side effect and James Marcus was killed by Dr. Alexander Isaacs so he could take control of it and turn it into a bio-weapon.
lionhead