Continuity mistake: When Bulgy is driving on the road next to the rails, Thomas can be seen pulling a train instead of being repaired at the foundry.
Continuity mistake: The mail van moves without a driver.
Audio problem: When Oliver arrives at the station, he has Percy's whistle sound.
Answer: Butch the breakdown truck must have pulled Gordon's tender all the way up the rails so the breakdown train can reach it and also Butch helped to get Gordon close to the winch.