Thomas, Percy and the Coal - S2-E1
Continuity mistake: When Thomas is being covered in coal, he is dirty in some shots, but in other shots he is clean.
Continuity mistake: At the beginning, Edward is pulling 5 cattle trucks. When he approaches the cows, he is pulling 4 cattle trucks.
Continuity mistake: Gordon's express train has 1 composite coach and 2 brake coaches when he passes through Wellsworth station. When he crosses the viaduct, he has 2 composite coaches and 1 brake coach.
Continuity mistake: Gordon can be seen next to Edward when Edward says "two big engines afraid of a cow?", but Gordon should have been on the turntable.
Continuity mistake: When Edward stops at the station, a close up of his whistle shows the sky is sunset dark, but when he arrives, it's bright daylight.
Continuity mistake: When Bill and Ben notice their trucks are gone, there are guards in front of them, two shots later, there is no sign of the guards.
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.