Revealing mistake: After the coach [Michael Jai White] told Billy that the group of people present all chipped in to pay his entry fee, there was loud cheering ("Yeah!) but it wasn't obvious from where the cheering was coming - except when there was a close-up of a particular person. Otherwise, the people in the crowd - especially those closest to him - did not appear to be cheering. The cheering, as well as the people in the background (green screen), must have been added. (00:04:08)
Revealing mistake: When Billy went outside onto the front porch (mostly not visible), there were tall plants in front of him and the porch's steps seemed to run parallel to the house, not perpendicular. After Billy got to his Jeep, there were no plants in front of the porch/steps and the porch's steps were perpendicular to the house. (00:07:40)
Continuity mistake: When Billy is walking (from his front porch) to his Jeep, the ground is brown, and he has to take several steps to reach the cargo area. When the camera shifts to a front view of Billy by the driver's side door, and he says, "Hi, coach", the Jeep is parked too close to the house for Billy to have taken that many steps to reach it and the grass behind the Jeep is green (not brown). (00:07:45)
Continuity mistake: The coach stopped his truck along the field, parallel to Billy's Jeep but not as far up the driveway. When the coach was getting out of his truck, the truck was much closer to Billy's house, parked at an angle to Billy's Jeep, and there was a gazebo behind his truck instead of the field. When the coach was talking to Billy by his Jeep (which was also now closer to the house), the gazebo can be seen but the truck was no longer there or visible. The truck's position varied without being moved. (00:07:53 - 00:09:40)
Continuity mistake: During the rain delay, Billy and Skeeter are sitting on the grass with wet - but not dripping - hair. After showing Billy's face dry a few times, he has a water bead on the tip of his nose, left cheek, and under his chin. Then, every other shot, the water beads are present. (01:21:32 - 01:22:10)