Factual error: In the final race, one of the horse's saddle pad flips up in the wind and reveals a synthetic-type foam rubber lining. This was unavailable in 1938.
Deliberate mistake: In the final race of the film, Seabiscuit performs a flying lead change at the gallop while crossing the finish line, in the famous shot taken underneath his neck. Horses normally only switch their leads around turns while racing; it's something done to relieve pressure on the leading foot. From taking the shot over and over again, the horse playing Seabiscuit was probably tired out and a little tender and began to perform lead changes in other places in an attempt to be more comfortable.
Continuity mistake: Early in the movie when Seabiscuit is shown getting "whipped as many times as possible" to break him, he is being whipped on the right side. Later, Red tells Wolfe prior to the match race not to whip him on the left side because that was where he was whipped as a baby.
Other mistake: In the hospital scene where Tom Smith, Mr. and Mrs. Howard and the groom are in the waiting room, it is mentioned that the evidence of the surgery taking time is noticeable by the light changing where Mr. Smith remains in the morning. In Seabiscuit, Mr. Howard, or Jeff Bridges, waits all night long to hear the results of the surgery, not Tom Smith.
Continuity mistake: In Seabiscuit's first race under Pollard, at the start the announcer says, "Pirate Cove breaks first with Geronimo on the outside. Silver Treasure is third followed by Seabiscuit." But when it cuts to Seabiscuit, there are six horses in front of him, placing Seabiscuit seventh. Seabiscuit would have to be barely moving to lose that much ground that fast.
Factual error: During the times where Red is in the hospital, they show Red several times with a cotton blanket with a certain type of weaving they didn't use until the 1960's. In the 30's they were still using single weave blankets. Kind of hard to explain, but older nurses could tell you.
Factual error: The license plates on the cars were dated TX 1937. I don't recall the movie ever happening in TX and they had not reached 1937 on the time line, yet.
Factual error: Orange twine was shown to tie bales of straw, twine of that type wasn't used until the late 70's or early 80's.
Factual error: When Seabiscuit and crew are returning by train to California after the big match race in Baltimore, the locomotive seen is a distinctive model used only by railroads in Canada.
Factual error: In a scene that is captioned: Tijuana, Mexico 1932; Jeff Bridges is being driven in a 1936-7 Buick.
Continuity mistake: In the scene where everyone is waiting for Red to get out of surgery, a nurse walks by with a stethoscope around her neck. This is a mistake for a couple of reasons. Number 1, it is a modern style Littman stethoscope that wasn't used until the 1970's. The old stethoscopes of the 30's look really different than they do now. Also, back then, nurses didn't routinely carry stethoscopes like they do these days to do assessments.
Continuity mistake: In the movie, War Admiral is described as standing 18 hands tall, compared to Seabiscuit's 15.2 hands. Although this is not historically correct (according to contemporary sources, both horses stood around 15.2 hands) the size disparity created by the movie is not carried on in the match race, where the two horses appear to be the same size.
Plot hole: Immediately after Seabiscuit injures his leg, the track vet tells owner Charles Howard that the horse will never race again. He offers to euthanize Seabiscuit, even though it was not a life-threatening injury. Even if Seabiscuit was unable to race again, a champion racehorse has more value as a stud horse. It is nearly inconceivable that a random vet would suggest this so early on. If anything, it would be "wait and see."
Factual error: The doctors tell Red he has broken his leg in 13 places, however the X-ray shown later is not indicative of an injury of that nature. The two fractures you see in the X-rays are considered non-unions (fractures that aren't healed properly and are unstable) but we should also see some type of hardware that would be needed for that many fractures. Surgeons have been using internal screws on fractures since the turn of the century.
Continuity mistake: When Red is telling the new jockey all about Seabiscuit's peculiarities, he tells the jockey not to use the crop on the left because a previous trainer had beaten him on that side. Earlierwhen the horse was working with that trainer, they show him being beaten on the right side.
Revealing mistake: After the race where Seabiscuit beats War Admiral, we see the train on the return trip home. If you look closely, the engine number on the locomotive is reversed, indicating that the film was flipped.
Other mistake: Red Pollard's operation for his injured leg occurs over many hours (as evidenced by the changing light and darkness on Tom Smith as he waits for the results.) Yet when the doctor appears to tell Smith that Pollard will walk again, he seems to be freshly shaven. Surely if he had just been involved in a lengthy surgical procedure, he would not have had time to shave.
Answer: Red asked for $10 because he needed to see a dentist, and Howard gave him $20.