Revealing mistake: In a close up of Edward, he has Thomas' whistle sound and no tender.
Plot hole: James appears in every episode before his introduction in "Thomas and the Breakdown Train." Also, James is supposed to be black, because at the end of the episode, James is told he will get a different coat of paint. (He is also black in the book).
Deliberate mistake: Due to the production order, Arthur can be seen at the quarry, but his introduction is 6 episodes later, in "The Spotless Record."
Factual error: Black smoke comes out of Henry's cylinders, when it should only be coming out of his funnel.
Revealing mistake: When Thomas leaves Dryaw, in the background, the biplane's propeller stops spinning, revealing that the propeller is actually a CD.
Character mistake: The narrator says that Thomas had never delivered the mail before, but he did in Season 4.
Other mistake: Mavis and Cranky should've realised that Thomas woke them up the first time he blew his whistle.
Other mistake: In the very first shot of Spencer, his coaches aren't textured.
The Biggest Present of All - S13-E16
Audio problem: When Henry and James are at the quarry, their whistle sounds are played out of order.
Audio problem: After Rex is hoisted back on the rails, Mike has Rex's whistle sound.
Continuity mistake: Gordon's Hill is much taller and steeper than it usually is. Also, when Belle reaches the other side of the hill, the tracks on the viewer's left disappear.
Other mistake: The Rev. W. Awdry is not credited in the title card of the episodes "Mike's Whistle", "Tit for Tat", and "Useful Railway." Only Andrew Brenner's name appears.
Factual error: At the beginning of the episode, the narrator says that Connor and Caitlin are faster than Spencer, but Spencer, an LNER A4, holds the world speed record for steam locomotives.
Thomas and the Sounds of Sodor - S16-E11
Deliberate mistake: When the engines are performing "The Sounds of Sodor", Emily, Thomas, Percy and Gordon have the correct whistle sounds but at a lower pitch. At one point, James has Emily/Henry's whistle sound, Mavis has her old "New Series" horn, and Thomas has James' whistle sound.
Duck and the Slip Coaches - S18-E8
Audio problem: At the beginning, Edward has Thomas' whistle sound.
Other mistake: In the Family Jr. airing, Davey Moore is not credited for writing the episode; Andrew Brenner is. This mistake was fixed in the UK airing.
Continuity mistake: UK Only: When Luke is coupled up to Skarloey's train, he has 5 trucks and a white brake van. When the deer jumps in his cab, the brake van disappears. And when Luke is heading towards the Castle, he has a brown brake van.
Continuity mistake: At the beginning of the episode, Henry is pulling trucks and Hiro is pulling nothing. In the next shot, Henry is pulling nothing and Hiro is pulling flatbeds.
Continuity mistake: When Thomas goes through Henry's tunnel, the first van in his train has one bogey. When he comes out, the van has two bogeys.
Continuity mistake: When Thomas leaves Knapford, there is a van in front of the brake van. When Thomas approaches Henry's tunnel, that van disappears.
Answer: Butch the breakdown truck must have pulled Gordon's tender all the way up the rails so the breakdown train can reach it and also Butch helped to get Gordon close to the winch.