Character mistake: The narrator says, "some trucks were left behind", but only 1 truck was left behind.
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.
Revealing mistake: After Gordon stops on the bridge for the cow, his wheels keep moving for 3 seconds.
Revealing mistake: When Percy stops on the bridge, white glue is on his middle lamp iron.
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.
Revealing mistake: Edward has wonky eyes in some scenes.
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.