Other mistake: When Ponies are flying back home from North Pole, you can see Cotton Candy among them. as a pegasus.
My Little Pony: A Very Minty Christmas (2005)
1 other mistake - chronological order
Directed by: Victor Dal Chele
Starring: Kelly Sheridan, Kathleen Barr, Tabitha St. Germain, Chiara Zanni
Continuity mistake: When two Pegasus ponies carry the "Here Comes Christmas" candy cane along the line of ponies, it passes Rainbow Dash four times.