Corrected entry: When Roger and Peter return to the truck yard to hotwire the second truck, if you look outside the front/driver's windows of Peter's truck, you can see a van driving quite close to the action. The four main characters are the only "living" people for miles, thus the van should not be driving around. (Unless some zombie suddenly got his driver's license.)
Corrected entry: When the SWAT team is raiding the building in the beginning, one of them knocks down a door through a barricade. Immediately many zombie arms shoot through and force the barricade off the wall. If the zombies were close enough to reach through the barricade, they should have been knocked back by the falling door, and they had no time to approach.
Corrected entry: If Fran was 31/2 or 4-months pregnant like Steve said, then she shouldn't have been able to lift them heavy cardboard boxes to block the door.
Corrected entry: In the sporting goods store, Peter tells Stephen not to try & shoot the zombies through the grill at the storefront - ".the openings are too small. bullets will wind up chasing us around in here." However, the camera cuts to the grill, which has openings of about 1.5" - well large enough to shoot through. And since the grill is made of a light metal, bullets could not possibly bounce/deflect off it.
Corrected entry: After Steve, Roger and Peter have secured the Mall so that no more Zombies can enter they than decide to kill the few remaining zombies left in the building. One of which is a zombie that took Rogers M-16 assault rifle. However at the end of the movie after the Raiders open the doors we see the same Zombie walking around and even gets to be in the final rooftop scene. He should have been killed and disposed of earlier because he was locked in the building, not out.
Corrected entry: In the store room at the top of the shopping mall in which all of the characters live, sleep etc. if you look at the boxes you will notice that the best before date on some of them is May 1962. The film was set in 1978. I doubt very much if a shopping mall would stock items which are 16 years out of date.