Visible crew/equipment: When Toad falls into the pond, in the shot from his point of view, studio equipment can be seen in the top left corner.
Continuity mistake: In the shot of Thomas stopping inside Knapford with his coaches, Henry is in his new shape.
Continuity mistake: When Henry leaves the docks, there's nothing on his footplate, but when he's out of the docks, there are suddenly 2 lamps on his footplate.
Revealing mistake: When Gordon puffs into the ditch his face looks wonky and wires are visibly attached to his cab.
Visible crew/equipment: At the beginning, a camera is visible in the top right corner.
Other mistake: The narrator says "the road left the railway...", but there is a road right next to Thomas.
Tenders and Turntables - S1-E15
Visible crew/equipment: In the close-up of James spinning on the turntable a crew member's face is reflected in his paintwork.
Thomas, Terence and the Snow - S1-E13
Visible crew/equipment: In the shot after Thomas pulls out of Knapford Station, the end of the set is visible.
Visible crew/equipment: When Thomas is on the turntable, a camera shadow is visible on the left.
Other mistake: When Thomas shunts Annie and Clarabel his eyes look wonky and Annie and Clarabel are missing their names.
Visible crew/equipment: As Henry approaches the green signal, the edge of the set is seen in the distance.
James and the Trouble with Trees - S5-E5
Revealing mistake: In the end of the episode, you can see James doesn't have his face fitted on correctly, as the gap between it and his eyes appears to be exposed.
Peter Sam and the Refreshment Lady - S4-E7
Other mistake: In two shots shown at the beginning, Henry is wearing Gordon's upset face mask.
Other mistake: After Toby breaks down, James pushes him directly to Knapford Station, not to the Works as it is said.
Other mistake: When Percy meets Thomas at Elsbridge Station, he has a water line across his boiler, even though the water only came up to his footplate.
Horrid Lorry - S5-E2
Continuity mistake: When Lorry 1 returns after falling into the sea, he is covered in algae and seaweed even though he wasn't submerged. He gains some more of it when Thomas sees him.
Factual error: The dam was built concaved from the water it holds back, but it would have been built convex in order to do so.
Other mistake: Edward is wearing James' sad face mask when he approaches the water column.
A Bad Day for Sir Handel - S4-E6
Revealing mistake: When Sir Handel derails, you can see a small rod sticking up out of the ground from the tracks.
Answer: Breakdown trains help the engines back on track.