In the scene when the pioneer settlers finally break character, there is a far shot behind all of them. You see the town murderer's black hair. But, when it goes to a front shot of all of them, the town murderer still has his wig on. He removes the wig then to reveal his black hair.
Near the beginning of the episode when Kyle points out the blacksmith is wearing a digital watch Pioneer Paul whispers "Damnit Chad" under his breath. However, later in the episode when the terrorists are interrogating the blacksmith, they pull out his employee information sheet and refer to him as "David Palmer"
The position of the terrorists' SUV is different when the police are taking the lead man to the police car.
Cartman's and Butter's drop from the traffic lights onto the top of the passing truck is only possible in an M. C. Escher space. The traffic lights are mounted in front of the intersection, above the street that runs from the foreground to the background. The truck passes on the intersecting street from left to right, which is a couple yards to the rear of these lights, and the boys even swing off the lights to the front. They should miss the truck by at least ten feet.
The pioneer village was set in 1864 but the cash register featured in the general store wasn't invented until 1879.