Revealing mistake: In a shot of Henry going around a bend in the country, you'll notice that the other side of the coaches is seen painted tan but the other side is painted green and white. This is because of budget limitations.
Thomas the Tank Engine & Friends (1984)
1 revealing mistake in Coal - chronological order
Starring: Alec Baldwin, Michael Brandon, Ben Small, Martin Sherman, Michael Angelis
Continuity mistake: Despite Henry's issue from "Coal" in Season 1 being resolved after the crash in "The Flying Kipper", also in Season 1, Henry needed special coal again from "Thomas and the Magic Railroad" until Season 16.
Bill and Ben: We're not playing. We're rescuing our trucks.
Trivia: The events of this episode were remade in CGI for the 2015 special, The Adventure Begins.
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.