Ronnie's soccer ball is the size of a ping-pong ball. In one scene it mysteriously changed into a regular size soccer ball that had enough mass to knock Maltravers onto a cart.
Ronnie hopes his home country, Brazil, will adopt soccer as a new pastime. Soccer was introduced to Brazil in 1884, 28 years before the Titanic sank.
Smoke rises from the fourth smoke stack. It was actually a dummy, used to ventilate the ship's kitchen.
The film implies that Captain Edward John Smith made it to New York City. He actually died in the sinking.
Captain Edward John Smith had a beard on board the Titanic, not just a mustache as seen in the film.
The film implies that lifeboats were available for every passenger. The ship had a limited number of lifeboats.
The ship was the "R.M.S. Titanic:" a "royal mail steamer," not a regular steam ship. However, Titanic lifeboats were actually labeled "S.S. Titanic", as depicted in the movie.
When one of Top Connors' children reads the newspaper describing the Titanic tragedy, Monday is spelled "Moday". The date on the paper was April 14, 1912, which was actually a Sunday, not a Monday. Additionally, the paper is marked "Internet Edition" under the banner headline.
During the CGI rotation of the Titanic, none of the passengers move.
The New York apartment window for the mice appears to be the same size as the human apartments.
The mouse orchestra plays jazz, which didn't become mainstream outside of New Orleans until the 1920s.
The manservant tells the criminal shark that the Titanic has to sink at midnight "and not a second less." In real life, the ship hit an iceberg at 11:40 pm.
In one scene, Smiley the dog is referred to as the "Piddler on the Woof," an obvious reference to the musical Fiddler on the Roof (1971) , which premiered nearly half a century after this story took place.
When the Carpathia is seen entering New York Harbor at the end of the film, the Empire State Building can be seen in the skyline. The Titanic sank in 1912, and the Empire State Building wouldn't be completed until 1931. It also appears smaller than it actually is in some scenes.
How did the Dolphins possibly know about Maltraver's plans to expand his whaling operation, when only Maltraver's manservant knew about it and no one else?
When the main mouse character dreams about Elizabeth, his friend says "She's a woman and you're a mouse." His reply "If there is one thing I'm not and that's a racist" makes no sense at all.