*snerk* I'm not to the level of being able to tell when they've got the wrong loco (despite my late father's better efforts!), although I do know just about enough to have at least frowned at an austerity in 1913.
However, I can actually go one worse than that: an adaptation of either an Agatha Christie novel or something similar had a train go into a tunnel with one locomotive at the front and come out being hauled by not just a different locomotive, but one from a completely different company and, hence, a completely different colour! That's a glitch that anyone paying at least a modicum of attention will spot.
It's almost as good as watching a low budget car chase and spotting when they've substituted the very expensive BMW for an extremely tatty looking Travant (not necessarily even the same colour) so that they don't crash the good car.......
I clearly need to find a better class of film!
And of course there was the business with the "Hogwarts Express". I gather that J.K. Rowling has, and exercises, considerable power to have the content of the Harry Potter films agree with her vision for the books; and in the books, it is often mentioned, and made very clear, that the Hogwarts Express is red. In the light of this, the choice of motive power for the H.E. in the films, was a little unfortunate. The preserved steam loco used in the role, is no. 5972 "Olton Hall", of Britain's former Great Western Railway. The Great Western was a railway of strong and very individual character, and many British railfans adore it with a devotion which goes beyond fanatical. The Great Western always painted its passenger locos dark green; it never, ever had a red locomotive. And of course, the loco used in the films had to be painted red. To quite a number of the more extreme Great Western fans, doing that to a G.W.R. locomotive was blasphemy. They were furious -- I believe a couple of death threats were even made.
I understand that the director of the first Potter film (I'm not really heavily into films, and his name escapes me) went round one of Britain's major steam preservation sites, from which he planned to hire a locomotive to haul the Hogwarts Express. No. 5972 is of a very handsome loco type: the director's eye fell on it, and it was love at first sight. Those in charge of the venue, foreseeing the problems about painting it red, tried hard to persuade the director to pick another loco -- one which was red already, or one of a variety which did not tend to attract fanatical worshippers -- but it was no use: 5972 was the one which the director had to have.