Bowled Out - S4-E18
Continuity mistake: When the diesel grinds to a halt and the camera switches to Duck and Stepney and then back to him, he is noticeably further away from the coaches.
Bowled Out - S4-E18
Audio problem: When James leaves Crovan's Gate, he has Smudger's whistle sound.
Answer: Breakdown trains help the engines back on track.