(at around 19 mins) After showing the tires on the truck getting completely punctured and deflating, in the next scene, just prior to hitting the big rock, the truck's tires are clearly still inflated.
(at around 1 min) In the beginning when Pluto kills the first researcher, you see the ax go through the mask, so the mask has a hole in it. When the researcher falls on the ground, his mask doesn't have a hole, it's just like it was.
(at around 14 mins) When Beauty runs into the gas station and Lynn goes after him, Lynn sees the bag on the table, the one with the ear inside it, then lifts a flap to peek inside the bag. The flap then falls down just the way it was, closing the bag again. When the gas station owner looks at the bag just after Beauty and Lynn left, the bag is wide open.
(at around 20 mins) The SUV changes position after striking the large rock. When it first crashes it is against the rock, later the vehicle has moved further forward and to the right.
(at around 48 mins) When all of the family except dad is in the trailer on the first night Bobby locks the door from the inside with a key. After Doug and Lynn say that they are going to sleep in the truck because it is too crowded they walk right out the door without unlocking it.
(at around 55 mins) The fire extinguisher used to attempt to put out the fire on the father is a CO2 (carbon dioxide) type. The man using it was holding on the nozzle, but anyone holding on to a CO2 nozzle would have their hand severely frozen and stuck to the nozzle.
At around 01:14 when Bobby is seen lying unconscious on the dirt and Ruby comes to check him, 2 droplets of blood are seen falling on Bobby's cheek supposedly coming from the leg of Beauty being eaten by Goggles up on a cliff. However the pattern of the blood spatter coincides with that of low velocity droplets being dropped from a distance of a few inches not from above a 15 feet high cliff.
Bobby said he has a clip and a half left. It's actually called a magazine.
(at around 1h 12 mins) The clear fluid poured onto the tire changes into a cinematographic "burn gel" just before Brenda lights it.
(at around 1h 20 mins) As Bobby and Brenda are loading the bodies into the van, Lynn can be seen breathing.
(at around 8 mins) Although he is totally grungy when he is looking at the human ear in the Styrofoam container, the gas station attendant's fingernails are nicely manicured.
at 1:23 when Doug is searching the house, he hears the mutants singing the 'Star Spangled Banner"; but the line 'o'er the ramparts we watched' is misquoted as 'o'er the ramparts we hailed'.
(at around 1h 15 mins) Signs on a chain-link fence and in the model town state that the area is managed by the U.S. Department of Energy, which was not established until October 1977. In fact, the U.S. stopped atmospheric tests of nuclear weapons in 1962, when the area would have been managed by the Department of Defense.
(at around 1h 15 mins) When Doug sees Catherine lying on the bed in Big Mama's house in the village, she begins to roll over, and we can see a hand reach up to stop her from rolling from the bed.
(at around 35 mins) When Doug stands at the edge of the enormous blast crater, a shadow falls along his arm, but there is nothing near him that could have caused this.
(at around 5 mins) At the beginning of the movie, after the title sequence and during a long crane shot toward the gas station, the film crew can be seen in a reflection on the green car's windows.
African vulture in New Mexico.
(at around 1h 18 mins) When Doug enters the house and takes the baby, Big Momma is watching Divorce Court (1999). The picture is crystal clear. There was certainly no cable in this area, and a broadcast signal, if it could even be picked up, would likely be of extremely poor quality due to the mountains. These mountains also block the family's radio transmissions.
(at around 13 mins) The father asks for directions to Interstate 88. They are a long way off being they are supposedly in California when I88 is located in both the greater Chicagoland area and upstate New York.