Other mistake: How does Dola know that Sheeta's pigtails were shot off? They had been outside in their aircraft the whole time and once Dola got Sheeta in a tight hug, the situation doesn't call for any time for her to explain what happened.
Other mistake: When Fievel And Tony reunite on the streets of New York, Tony gets a piece of cheese off of a mouse trap. Watch that piece of cheese, cause Tony throws it up in the air, and you never see it come back down. (00:33:25)
Other mistake: The credits for the movie say that they are in alphabetical order, but Peter Cullen is listed before Scatman Crothers.