Revealing mistake: When Murdoch asks Gordon "What decorations will you have, Gordon?" his left eyebrow (viewer's right perspective) is scratched.
Visible crew/equipment: When James enters the station, a camera shadow is visible.
Continuity mistake: When Gordon hits the apples, he just bangs into them, no damage, but in the next shot, the apples are visible and smashed and the cart is crushed and on its side.
Plot hole: Bulgy is seen in his season 3 paint job, but in Bulgy Rides Again he's a veggie bus.
Visible crew/equipment: When Murdoch puffs by a field, a stage light is reflected off the coach's windows.
Deliberate mistake: When Thomas goes by the level crossing, a close up of Thomas is shown but it's the same footage from season 1, only flipped. Because of this, Thomas' number is mirrored.
Visible crew/equipment: When the banner hits Gordon, in the next shot, a scaffold is very visible in the trees on the right. (Visible in Wide screen version only).
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.