After acquiring the injured horse, Ben is going to take the horse back to his farm. When the truck is shown pulling up to the stable, there is obviously no trailer; however, in the next scenes, the red trailer is shown hooked up to the truck.
When Sonador is following Cale (going left to right in a pen of some sort) you can obviously see that Sonador is a gelding, when she is supposed to be a filly.
In the shot right before the horses go into the gate for the Breeder's Cup Classic, the camera pans out to reveal a field of horses that are obviously not in the big race. They are wearing white saddlecloths instead of Breeder's Cup purple ones and are part of a real race field at Keeneland Race Track where the scene was filmed.
After losing the horse in a claims race, Ben is seen talking with Cale in the stable. Near the end of the scene the camera is zoomed into Ben's face. Cale is leaving the stable and Ben's eyes look to his right as Cale walks past, yet the next camera angle shows Cale walking out to Ben's left.
Near the beginning of the movie when the vet has finished his examination, Ben is shown holding an x-ray which the vet says is the one from the track and he says it confirms his x-rays of a spiral fracture of the cannon bone. Also Ben tells Cale that it is 'non-displaced', however this x-ray clearly shows a displaced fracture of the radius bone from the knee up about five inches long (all x-rays are life size). The cannon bone (also called the metacarpus) is below the knee joint. The x-ray is also clearly marked with an 'L' meaning 'Left', but all scenes of the horse with the cast show it on the right front leg.
In the race in which Sonador runs third and is claimed, the TV screen showing the start reads "The Fairgrounds". This is the name of the racetrack located in New Orleans, Louisiana (not in Kentucky). In fact, The Fairgrounds is the oldest thoroughbred racetrack in the United States; racing began there in 1852.
When Sonador overtakes the field, it appears she is the only horse on the correct (left) lead, therefore the rest of the field is struggling more to run counter-clockwise on the incorrect (right) lead. A horse's lead is the front leg that reaches the farthest forward ("leads") with each stride.
In the scene where Cale and her father are talking about the 3 mares that Pop Crane had kept, you do not see a horse trailer in the field behind Cale. As they are talking a horse trailer suddenly appears behind Cale in the field.
When Ben, Cale and Pop pull into the prince's driveway, you can see a stationary SUV on the road behind them.