Gladiator
Russell Crowe's character is nicknamed "The Spaniard," but this word didn't even exist until centuries after the movie was said to take place. "Spaniard" is derived from the French "Espaignart," adopted into Middle English around the 1500s. Gladiator is set in the year 180 a.d.
The Aviator
"I want ten chocolate chip cookies!" says Howard Hughes, played by Leonardo DiCaprio in The Aviator. "Medium chips. None too close to the outside." An interesting request, not only due to its specificity. The chocolate chip cookie wasn't introduced until 1930—two years after the film was set to take place.