During a game against the Orioles (right after the taunt "Get a job, Wiggin, get a job!"), an overhead shot shows no base-runners. Henry pitches, the batter hits the ball; then the next shot, from the hitter's point of view, shows a runner starting off from second base.
During Piney's song in the clubhouse, coach Joe is shown holding the deck of cards in his hand. The next cut shows him with all the cards spread out on the table. No time has passed since the song is marking the time.
During a rainstorm, the grounds crew is shown pulling the tarp over the field. After a locker room scene, the next exterior shot shows only the home plate area covered, and the rest of the field open to the rain.
When Piney Woods is playing the guitar in the locker room during the rain delay, he clearly has a splint or heavy bandage on the index finger of his right hand. Such an injury would make it very unlikely that he would play. In a scene later that night set in a hotel room, Piney has no apparent finger injury.
Although released in 1973, the Oakland A's and the Cleveland Indians are still wearing their uniforms from the 1971 season. This was done because the real Major League footage in the film was from the 71 season.
The Yankees (Mamouths) are seen in the film playing Pittsburgh and Cincinnati. Both Pittsburgh and Cincinnati are National League Clubs and wouldn't play the Yankees unless it was the World Series as there was no interleague play before 1997.
Paul shoots the light in the hotel room using a single action revolver, which requires manually cocking the hammer. However, the hammer is clearly in the down position and his finger is not even on the trigger.
In the same at-bat Bruce Pierson is seen facing pitchers from the Pirates and Indians.
All game action was shot at Shea Stadium and Yankee Stadium, but the Mammoths wore their home white and road gray jerseys at both fields.
The same tunnel is used to represent both the home and away venues, the only difference being the removal of a stretcher hanging from the wall in the away venue.