As Ernest Torrence is sitting and negotiating for the sale of Tommy Boy, his pipe switches from his left to right hand and his julep switches from right to left.
The medium shots and close-ups of Uncle Ben bottle-feeding the young colt Tommy Boy don't match.
Tommy Boy is shown arriving back at the farm where he was born. Driving up in the trailer, he is not wearing a blanket. When the trailer is opened, he is wearing a blanket - which Sammy is then told to remove.
At the finish of the Kentucky Derby, there are a couple shots of the jockey on the number 8 horse (Tommy Boy) wearing a different jersey.
When Southern Queen falls in the mud, a trip wire is clearly visible on the horse's hind leg.
When the mob is listening to the race on the radio, the camera pans some faces in close-up, and a clear shadow of the boom microphone is visible on the wall behind them.
At the casino's roulette table, the croupier is seen raking in chips that are clearly off the playing field.