Other mistake: In some shots of Percy in the water, his boiler is chipped.
Other mistake: When Percy meets Thomas at Elsbridge Station, he has a water line across his boiler, even though the water only came up to his footplate.
Thomas the Tank Engine & Friends (1984)
2 mistakes in Percy's Promise - chronological order
Starring: Alec Baldwin, Michael Brandon, Ben Small, Martin Sherman, Michael Angelis
Bill and Ben: We're not playing. We're rescuing our trucks.
More trivia for Thomas the Tank Engine & Friends
Question: How did they get the broken down train at the scene of the crash without any calls?
Answer: Breakdown trains help the engines back on track.