Continuity mistake: The E.M.T.'s legs in back of ambulance when first shown are hanging over the red line on bumper. When they cut to farther shot, The legs are now pulled up more. (00:02:05)
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: When Ana and Kenneth are walking through the tunnel, as Andre fires at them, Kenneth is standing in the sunlight shining in to the tunnel. When it cuts to Kenneth and Ana bending down the sun isn't shining inside the tunnel anymore. (00:13:55)
Continuity mistake: After Andy shoots the zombie that looks like Jay Leno, there are shots of the characters looking through binoculars. Tucker's and Steve's binoculars still have the lens caps on. (00:58:05)
Continuity mistake: At the very beginning, when Luis attacks Ana, she escapes into the bathroom and falls over into the tub. The rug on the floor is folded back in the shot from the top, but it is flat when Ana steps out of the tub.
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.
Continuity mistake: When the group goes to rescue Nicole from Andy's shop it it is evening, when they return and must evacuate the mall it's night, but soon as they clear the horde in the parking lot it becomes early morning.
Continuity mistake: About 3/4 of the way through, CJ is on the roof of the gun shop and blows up a tank of propane to clear the zombies so everyone can escape. The truck that was blocking the door was their only way in and out of the shop. On their way into the gun shop you see two zombies follow them through the truck to the shop's entrance, but when he blasts the propane, somehow I guess they get cooked. My nitpick is that when CJ goes the same path as the others, there is a dead zombie blocking his exit through the truck's door. If the others already went out that same door they would have had to move that burned zombie to get through the truck.
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