Factual error: When the shop vac shoots the golf ball at Mr. Wilson's gonads, it only affects him for around ten minutes. The shop vac was able to shoot a glob of paint over 50 feet in the air so the speed and impact of the golf ball would have done much more than put Mr. Wilson in extreme pain for a short while. The impact would have likely caused internal bleeding, swelling, causing him to vomit, probably a rupture, requiring him to be hospitalized. There is no way he is walking away from that, he wouldn't even be walking at all.
Factual error: For a baseball movie, you would think they would have known the rules of the game better. There is a scene in which Henry uses the "hidden ball trick" to pick a runner off of first base. He stands on the rubber on the mound with only the rosin bag in his hand while the first basemen holds the ball. It is a violation for him to stand on the rubber or straddle it without the ball in his hand and is called a "balk". Technically the runner should have been awarded second base.
Factual error: Although the movie is set in 1962, when Rodriguez jumps the fence of the junkyard, a red door from a '73-88 GM pickup can be seen in the background.
Factual error: The footage of the garden blooming in the spring includes a shot of a monarch butterfly emerging from a cocoon. The monarch is very rare in England, usually found in the southwest; so this footage is more likely from North or Central America where the insects are commonplace.
Factual error: The movie feels the need to justify the fact that everyone in 1603 Japan happens to speak English (something most kid movies just gloss over) by explaining that they are trading with Great Britain, and therefore the locals picked up the language. That's real cute, but also blatantly false. Trade with the British empire was rather sparse, mostly with Dutch mediation, and knowledge of the English language was practically nonexistent - here, any peasant and even kids are practically bilingual.