Revealing mistake: In a close up of Edward, he has Thomas' whistle sound and no tender.
Continuity mistake: When Edward is pushing trucks over a turntable, when he stops, he is very close to the trucks, when the camera changes, he moves back a bit. (Note the tank the Fat Controller is standing on).
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.