Continuity mistake: In the beginning when Dr. Dandewar hangs up the phone, there is an orderly pushing the cleaning cart in the distance behind Ana. When it cuts to the close-up, the orderly disappears with the cart. (00:00:45)
Continuity mistake: In the opening scene after Anna's neighbor is hit by the ambulance, his body is visible lying in the street. However, when Anna is driving away you cab see the street through her car's rear window and the neighbor's body is nowhere to be seen.
Other mistake: When Kenneth and Andy exchange via white board about Fort Pastor, you can see a guy chilling on the roof of a building nearby in the background just over Andy's head when he ask " so what's the bad news." He is not trying to get the attention of either Kenneth or Andy. (00:47:28)
Answer: It was actually explained in both versions that the zombies went to the mall because it was a place of familiarity, a place that they could remember even if they didn't know why.
Tobin OReilly