Continuity mistake: After Ben arrives, he goes outside to exterminate zombies who have been attracted to the house. There were three, the one he hit with his truck, the one on the porch, and one in the yard that looked to be wearing a leather jacket. He kills the one on the porch and the one in the yard, but he doesn't kill the one in the jacket. After he kills the one he hit with the truck and begins to walk back up the hill to Barbara, you can see him in a full, empty yard. The third zombie seemed to have disappeared.
Continuity mistake: After the sequence where Ben tells Barbara she is losing it and then comforts Judy Rose, we see Barbara reloading a shotgun and Ben in the background nailing a white door in the next room. After it cuts to a shot of Judy and Tom nailing another door, we see Ben knock over a table while holding and putting in place the same door he had previously been nailing the window shut with.