Revealing mistake: At the beginning, when one of the black trucks has an accident, whatever is making the dramatic sparks is still running when that part of bodywork is off the ground. (00:05:25)
Revealing mistake: In the early aerial shots of Raccoon City, look to the left of the screen and you can see the CN Tower, a very recognizable landmark that is definitely in Toronto, not Raccoon City. This is due to the fact that film was shot in Canada. (00:05:25)
Revealing mistake: Resident Evil Apocalypse was shot in Toronto and the filmmakers wanted to use the city surrounding the CN tower to be Raccoon City. They edited out the CN tower, however they missed a brief glimpse at it. It's shown really quickly in between when Angie's vehicle crashes and when it stops. (00:05:25)
Revealing mistake: Near the end of the film when the zombies are shuffling up what looks like a parking ramp towards the escape helicopter, in several shots it's painfully obvious that some zombies don't have any makeup at all and a good portion are walking normally, unlike their shuffling comrades. One with blonde hair is even using a handrail. (01:15:20)
Revealing mistake: Nearly at the end, the scientists find Alice's body at the waterfall, one of the men lifts up the cloth to take a look at her face. Her face is badly burned on one side and she is pronounced dead. However, take a look at the left side of her neck, you can see her either gulp or take in a quick breath of air. (01:19:05)
Revealing mistake: When Alice fixes her broken finger, you can see that the finger (and the entire hand) is made of rubber. This is even more obvious on the Blu-ray.
Revealing mistake: When Yuri gets bitten while the SWAT team, along with the local PD, fight the zombies on the streets, Carlos and Yuri almost get bitten by a zombie, but they are saved by their 3rd member. Right after that we see a sign reading "Pizza Pizza" which is the largest pizza company in Ontario, Canada. There are no locations in the US.
Answer: The newspaper clippings we see in her apartment at the start refer to a 'mansion incident' - this in fact relates to the events of the first Resident Evil game, when Jill and other STARS members were trapped in a mansion overrun with the T-Virus. By the end of the game Jill knows exaclty what the T-Virus is and what its effects are.
Even though it mentions it in the newspaper clippings in the movie she wasn't even at the Mansion so therefore she wouldn't have known about the t-virus in the movie.
She was at the mansion prior to the events of Apocalypse, and one of the first ones to know about the virus before it hit Raccoon City.