Plot hole: How could Gordon's driver tell the station master that Gordon couldn't get up the hill? There are no phones on Gordon's hill.
Audio problem: When Gordon backing down to the bottom of the hill, you can hear brakes screeching, but Gordon's wheels are still moving.
Visible crew/equipment: At the beginning, a camera is visible in the top right corner.
Other mistake: Edward is wearing James' sad face mask when he approaches the water column.
Answer: Breakdown trains help the engines back on track.