Continuity mistake: In the last scene of the movie, Bobby's wedding, his long-lost father Roberto drives his car in front of Bobby's lawnmower and stops in the middle of the street, the front of the car almost perpendicular to the curb. After Momma tackles Roberto, the shot when Bobby drives off shows the car parked parallel to the curb.
Continuity mistake: When Bobby is first hired by Coach Klein, and the guys knock down the table with cups of water, Bobby and the coach talk. Two girls, one in a white t-shirt and the other in a black sports-bra type top, walk past Henry in the background in the wide shot, and again in the next close-up.
Character mistake: In the short scene where Bobby is standing in front of his class holding a large molecule, the diagram of the molecule can be seen on the blackboard. In part of this diagram a carbon atom 'C' can be seen bonded to five other atoms. As all good chemists know however, carbon can only form four bonds and so this molecule could not possibly exist.
Continuity mistake: In the scene of the last play of the Bourbon Bowl, with time running out the quarterback catches a pass from Bobby for the winning touchdown. While catching this pass, it shows him reaching back with his left hand to snag the ball while he is falling down on his left side. But the next shot from the beyond the end zone shows him hitting the ground on his right side.
Other mistake: At the beginning of the movie when Bobby starts being waterboy for Coach Klein, the players are on the field giving him a hard time. Bobby is on the sideline and the quarterback is making fun of him, which winds Bobby up and he runs onto the field tackling the quarterback. Even though Bobby hits him from the front, knocking him onto his back, a clump of grass somehow appears in the quaterback's facemask.
Other mistake: When Bobby recovers the onside kick, he recovered it on the 43-yard line, which is where the ball is spotted (the scoreboard even shows this). However, there was an unsportsmanlike conduct penalty with the late tackle (and a flag was thrown so we know the ref didn't miss the penalty) so the ball should have been spotted on the 28-yard line. (And there's no question there were no off-setting penalties).