The montage of Texas League opposing teams includes "Galveston." Galveston did not have a team in the league at that time.
When Dean is pitching to the Yankees, the announcer says that Frank Crosetti is at the plate. He is wearing number 3. Crosetti only wore numbers 1 and 2. Ruth was the only one to wear 3.
Dizzy is shown pitching to Lou Gehrig in the World Series with #4 on Lou's jersey batting right. Gehrig was left handed and batted left.
When Dizzy is pitching for the Cubs in the World Series, the Wrigley Field scoreboard behind him shows a full schedule of other games being played at the same time.
Game scenes in Sportsman's Park, in which Dizzy Dean pitches as a Cardinal, clearly show light towers in the background and the shadows of stadium lights on the field. Sportsman's Park did not have lights until 1940, three years after Dean's last game with the Cardinals.
An establishing shot of the Detroit Tigers' venue for the 1934 World Series shows its name as "Briggs Stadium", which it wouldn't become until four years later. In 1934, it was still named, "Navin Field".
Dean's Cardinal cap is depicted bearing the city's initials, "St L". During Dean's years with the Cardinals, the caps were white (or gray, for road games) with red pinstripes, a red bill, and no lettering. The "St L" logo first appeared in 1940.
Patricia's dress and hair styles are of the early 1950's rather than the 1930's.
One of the New York Yankees who faces Dean in the 1938 World Series bats right-handed and wears Number 4. The only Yankees player to ever wear Number 4 was Lou Gehrig, a left-handed batter. Gehrig was with the Yankees when the team initiated uniform numbers, and the number was retired when Gehrig himself retired --- the first time such an honor was bestowed upon a player.
Dan Dailey's southern accent sounds very inauthentic.