In different shots after the game with Texas Gentile, Van Johnson's (no character name) costume changes from coat, tie, and white shirt to a sports shirt.
(around 52 mins) When Pepe and ensemble start to sing "Look Out", Connie Casey exits the scene. However, when the scene progresses through the various edits, Casey constantly appears and disappears, and also changes standing position in the ensemble crowd.
When Pottawatomie is playing Texas, Jojo says the score is 26-0. Clint says "Texas has scored only once this quarter?", intimating that it is at least in the second quarter. But when Desi is injured and the three other bodyguards decide to go ahead and play for Pottawatomie, one of them scores a TD. Then the scoreboard is shown and it says that it is 26-7 with 8 minutes left in the first quarter.
The college is supposed to be in New Mexico where there are no Joshua Trees but Joshua Trees (native to the Mojave Desert) show up in a few scenes.