Deliberate mistake: When Rocky meets the kid that has his entire overbody and head covered in gypsum you can see that it is fake as the gypsum on the kids head is loose. The kid can move his head inside of it. (00:12:35)
Deliberate mistake: When Al is looking through the binoculars, Steve's Yankee logo on his jersey is on the wrong side. (01:25:00)
Deliberate mistake: When Buddy's dog box falls out of the back of the truck the dog box is empty.
Deliberate mistake: When Lisa fights off Stef in her car when they go parking and they both sit up straight, it is quite clear they're not sitting in an actual car, but on a bench made to look like it's supposed to be in a car.
Deliberate mistake: When everyone is surfing at night, the sound of the waves in the background is significant, as it should be. However, at one point, when Keanu and Lori are having an intimate conversation on the water, the sound of the waves disappear. The wave sounds resume in the next scene.
Deliberate mistake: In the beginning of the movie when Happy first discovers his swing, the balls that hit the people down the street are never visible upon impact.
Deliberate mistake: The floating candy bar that clears everyone from the swimming pool is a Baby Ruth, but Baby Ruths don't float, they sink like a rock.
Deliberate mistake: The film uses Milwaukee County stadium,instead of Cleveland Stadium, as the home of the Indians. (00:26:10)
Deliberate mistake: I have participated in several amateur karate tournaments over the years and I have yet to see one that is full contact without any protective equipment whatsoever, especially one in which all of the participants are minors. All of the contestants should at a minimum have had mouth guards, gloves and foot pads.
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.
Deliberate mistake: Some of the same crash scene footage is used before and after the Applebee's commercial break.
Deliberate mistake: During the Hall of Fame sequence at the end, Dottie sees the display about Jimmie hitting 58 home runs and there is a long wide shot of it as she stands next to it. Then there is a close-up of the bottom of the text which says born 1906 - died 1987, which wasn't present during the wide shot a moment earlier. The filmmakers likely saved this for the close-up for dramatic effect, but by blocking the initial shot without that part obscured it makes the text magically appear out of nowhere.
Deliberate mistake: In the final fight, two master Brazil Jujitsu fighters, one an instructor and the other a champion, execute rear naked chokes without the requisite body locks, using the legs to control the body. In the first case, Mike was able to escape the choke by flipping backwards, which a body lock prevents. In the second case, Mike was able to strangle Silva even though any trained fighter could prevent it by simply twisting their body. (01:30:00)