Character mistake: Karen says the train she spotted was going north. There was no way to know which way the train was going to go.
Frosty the Snowman (1969)
1 character mistake
Directed by: Arthur Rankin Jr., Jules Bass
Starring: Paul Frees, Billy De Wolfe, Jackie Vernon, Jimmy Durante
Other mistake: The narrator says that the train stopped to let the train filled with Christmas carolers go by, but the train passed after the train had already crossed the tracks, so there was no need to wait. (00:19:30)
The Magician: You silly children believe everything you see. When you're grown up, you'll realise that snowmen can't come to life.
Karen: But we.
The Magician: Silly, silly, silly.