Revealing mistake: Whenever Ralph is driving Travers in the limousine and the exterior of the car is seen in a long shot, there is no one riding in it other than the driver. From every view point of the windows that can be seen, there is no passenger inside where Travers is supposed to be seated.
Saving Mr. Banks (2013)
1 revealing mistake - chronological order
Directed by: John Lee Hancock
Starring: Tom Hanks, Colin Farrell, Emma Thompson, Ruth Wilson
Factual error: The scene at LAX incorrectly has signage for Trans World Airlines as Trans World Airways.
Walt Disney: We can't make this film without the color red - it's set in London, for Pete's sake!
P.L. Travers: And?
Walt Disney: Well, there's buses, mailboxes, guard's uniforms, the English flag...
P.L. Travers: I understand your predicament, Mr. Disney. It's just that - I don't know what it is, I'm just suddenly very anti-red. I shan't be wearing it ever again.
Trivia: Tom Hanks is the first actor to play Walt Disney in a mainstream feature film.
Answer: The dog is either a Skye terrier or a French Briard. Since it is white and has a long tail it is most likely a mixed breed, since the scene is supposed to be in Australia, it may be a mixed terrier and Australian sheep dog mix.