Factual error: In the beginning of the film, the Dowager Empress Marie states that the year is 1916 and that they are celebrating the 300th anniversary of their family's rule. The 300th anniversary actually took place in 1913. (00:01:05)
Factual error: Although cars are seen driving on the right-hand side of the road for most of the film, one overhead shot shows UK-style "give way" lines across the left-hand side of the road.
Factual error: When Young Hercules makes the pillars fall in a Domino effect, they go both ways. However, if this were to happen, they would stop the domino effect when they reach the entrance to the market, which doesn't have pillars. The pillars are not in a circle, so there's no way they can both stop at the top of the ring, where the pot seller is. The only way for this to work is if Hercules started the Domino effect at the entrance of the market, with pillars directly across from each other, which he doesn't.
Suggested correction: He throws the pillar he holds towards the opposite side causing it to fall as well.
They do a pulled back shot that shows it falling from the top of the ring.
Factual error: Why do the astronauts on Mars and the crew on Earth have the conversations as they do on the phone? A message sent from Earth would take about 20 minutes to arrive at Mars and vice-versa.
Factual error: During the remote control car chase the bad guys' minivan drives directly over it at one point. From the view of the toy car, you can see a driveshaft running down the centre of the undercarriage, which would be impossible on a front-wheel-drive vehicle like the Nissan Quest they're driving, which use half axles to drive the front wheels.
Factual error: When Buddy's owner chases Buddy and Josh, you can clearly see his car is in park.
Factual error: In the scene where the Professor Phillip first sees his creation (Flubber), he states that Flubber is 77 degrees Kelvin. Theoretically speaking, 77 degrees Kelvin is extremely cold, about -195 degrees Celsius (or -320 degrees Fahrenheit). The professor was handling Flubber with his bare hand at one point so he should've acquired one heck of a cold burn.
Factual error: At the end of the movie, Wally pushes Kyle into the big vat of fudge after he made fun of the Beaver. When fudge is in liquid form, it is extraordinarily hot, and would have burned the child severely.
Factual error: As Danny arrives in Hollywood at the beginning of the film, the Hollywood sign can be seen. The film is set in 1939 so the sign should still read Hollywoodland, as it did until 1949. (00:03:00)
Factual error: When the girls are heading to the Albert Hall, they take a very bizarre route. For them to cross Tower Bridge and pass Battersea Power Station, they would have to travel right through the centre of London, where the Albert Hall is located.
Factual error: The establishing shot of the film shows an art gallery with the subtitle 'The Royal National Gallery, London'. Not only is there no such museum (its closest match being simply the 'National Gallery'), but the shot actually shows the Tate Britain, complete with visible red banner outside saying 'Tate Gallery'.
Factual error: George's "dog", Shep, is an Asian elephant. However, the jungle scenes take place in Africa.