Half the fun of watching movies it to spot the places where you know 'that's ridiculous' but carry on . Granted, it's usually not worth complaining to the producer or whoever. However, there is nothing wrong with intentionally looking for anachronisms, errors, etc., whether in railways, cars, hospitals, weather patterns or whatever you know a bit about. It's just a bit of fun, nothing to get offended by.
Have only just noticed this thread (I don't usually look at "Traction & Rolling Stock"). I do feel that
@pdeaves's view of matters above, is the best to take as regards the dispute: "being wrenched out of the film's action by something inaccurate / incongruous", versus "it's entertainment -- suspend your disbelief, for heaven's sake !". Nitpicking re inaccuracies can be done in a spirit of fun, rather than outrage.
I recall once seeing a book with the title "The Killjoy's Guide to the Cinema". It was an essentially humorous, tongue-in-cheek work: devoted to enumerating, film by film, assorted "wrong stuff" -- what the author referred to as "dreck" -- in numerous classic, and not-so-classic, cinematic offerings. The "dreck" concerned was, on the whole, a matter of general -- in the main decidedly small -- anachronisms / continuity errors / implied contradictions, rather than inaccuracies which only an expert on a particular subject would be aware of or be bothered by. It seemed clear that the author absolutely loved this avocation of his.
I think my favourite "railway thing got wrong in a film", has to be the one in
Women In Love, released 1969. The film is set in 1920: one scene shows one of the chief male characters racing, on horseback, a colliery train on the parallel rail line. The train is hauled by a National Coal Board "Austerity" 0-6-0ST, fitted with a Giesl ejector. (Dr. Adolph Giesl-Gieslingen was no doubt a genius; but it's hard to see him as a sufficiently precociously brilliant teenager, to have been able by 1920 to invent his improved-draughting device and sell it to Europe's railways in general.) Of course this is a case of -- per various posts in the thread -- for the enormous majority of the watching public, "a train is a train is a train" -- for a 1920 scene, so long as the train's steam, they'll be happy.
I could ignore TOPS codes on goods wagons supposedly in wartime Poland (The Password is Courage) but I did find the words "British Railways" on the side of a supposedly Victorian locomotive (The Secret Agent) jarring.
I happened some years ago, to encounter a cunning new stratagem employed by some people, to soothe threatened inner turmoil over inaccuracies /incongruities in (using the term very broadly) "fiction". Namely: rope in the "alternative history" scene, and assume that the past of one's own time-line was, in a few basically tiny and unimportant things, different from how official history tells it.
This ploy was found by me, among fans of the American fantasy / alternative-history novelist S.M. Stirling. He's written a long, long series of novels (which I came to find awful, and largely destroying of my former liking for the guy's works -- but that's by the way) about a cosmic catastrophe which strikes Earth in IIRC 1997 -- resulting in technology suddenly being thrown back most of a millennium, and the rapid death of 90%-plus, of the planet's population. Bound up with these novels, is stuff concerned with the output of the authors A. Conan Doyle and J.R.R. Tolkien (on whom Stirling is keen to obsession-point); whereby in a few very small details -- as well as everything changing from our historical time-line at the 1997 cataclysm; our own history pre-cataclysm, was also a tiny bit different.
Thus: in
The Secret Agent (1880s setting, if I'm right) -- loco emblazoned "British Railways". One might speculate (without harm to the cloak-and-dagger stuff) that, like quite a number of continental European countries in the 19th century, the UK had had a mixture of privately-owned railway undertakings, and State ditto: the latter being 19th-century "British Railways". Similarly with the recent televised
War of the Worlds, with Great Western trains serving parts of Surrey: it would seem not a hugely far-fetched thing to imagine, that railway development west and south-west of London had gone a little differently from our historical time-line (which would have been "just as actually was" in all other respects); with trackage in Surrey, of the -- or a -- Great Western Railway.