Continuity mistake: Thomas appears to be damaged and dirty after his accident but in the final scene, he is undamaged and clean.
Continuity mistake: When James passes Edward at Knapford, Edward's train does not have a brake van. But two shots later, it does.
Henry Gets the Express - S20-E3
Continuity mistake: Throughout the scene when he is at Brendam Docks, Gordon's paintwork is noticeably darker.
Continuity mistake: Sir Handel was just near the turntable when Samson approaches the Blue Mountain Quarry, but a few shots later, Sir Handel has moved to a siding.
Diesel and the Ducklings - S20-E4
Continuity mistake: When Diesel keeps James and Gordon waiting, they are at the top of the hill, but a few shots later, they are at the bottom of the hill.
Answer: Breakdown trains help the engines back on track.