Thomas, Percy and the Coal - S2-E1
Visible crew/equipment: In the restored version, studio equipment can be seen when Toby pulls Annie and Clarabel and at the water tower near Tidmouth Station (at the top of the screen in both scenes).
Revealing mistake: Max's wheels can be seen moving backwards when he is actually driving forwards. Also, both Max and Monty's steering and wheel speeds are out of sync with their movements. These events happen throughout the episode.
Continuity mistake: Thomas appears to be damaged and dirty after his accident but in the final scene, he is undamaged and clean.
Revealing mistake: When Toby asks Thomas if he took on enough water, Toby's eyes are wonky.
Continuity mistake: James and Edward are on the mainline at first, but then they overrun the platform at Dryaw station, which is on Thomas' branch line.
Visible crew/equipment: When Thomas puffs away from Toby, two steam platforms are visible.
Audio problem: In some American home video releases, when Thomas climbs Gordon's Hill, the music and sound effects are briefly muted and a voice says, "Look out for the train." The voice can still be heard in some other releases, but the music and sound effects are not muted.
Factual error: A "wonky" whistle doesn't sound like a slide whistle, it should sound like a weakened version of the correct whistle mixed with the hissing sound of steam. A "wonky" whistle would also leak steam constantly instead of being blown like a normal whistle.
Continuity mistake: When Thomas is organizing the trucks, in a second close-up of a truck, the background disappears in mid-sentence.
Visible crew/equipment: When Stepney puffs through the fog after dropping off the stone loads, studio equipment can be seen in the top left corner of the screen.
Visible crew/equipment: When Thomas says to Emily, "Give them back!", studio equipment is visible on the top-right corner of the screen.
Visible crew/equipment: When Henry puffs under the bridge, studio equipment can be seen in the top left corner.
Visible crew/equipment: When Diesel is on the turntable, camera equipment is reflected in the windows for several moments. (00:02:00 - 00:10:00)
Thomas, Percy and the Squeak - S6-E21
Other mistake: When Thomas sees Percy at the washdown, Gordon's front and rear bogie wheels are derailed.
Lady Hatt's Birthday Party - S5-E4
Continuity mistake: When George drives into the ditch, the Fat Controller prematurely tips over, then tips over again in a closeup shot.
Other mistake: In some shots of Percy in the water, his boiler is chipped.
Revealing mistake: A wire can be seen between Rusty and his coach after the workmen have removed the ice from Skarloey.
Henry Gets the Express - S20-E3
Continuity mistake: Throughout the scene when he is at Brendam Docks, Gordon's paintwork is noticeably darker.
Thomas and the Missing Christmas Tree - S2-E26
Other mistake: In the shot of Donald, (or Douglas) Gordon and Henry, Donald has Edward's face.
Other mistake: When Bill and Ben are pushing each other, Bill has no eyes, Bill and Ben's faces are slanted at the bottom, and Ben's cylinder pipe is crooked along with a tack above Bill's face seen.
Answer: Breakdown trains help the engines back on track.