Revealing mistake: The waves hitting the ship are obviously being sprayed by a hose.
The Fogman - S6-E6
Revealing mistake: A piece of slate is already seen on the ground from a previous take before the slates hit the ground.
Revealing mistake: In a shot of Duck at the smelter's, a hole is visible on his running board.
Thomas the Jet Engine - S6-E22
Revealing mistake: After Cranky unloads the jet engine, it is already turned on.
Revealing mistake: Peter Sam is already missing his whistle even before it gets knocked off by the branch.
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.