Which I suspect could have been the single track Bluebell line anyway?
Few film or TV producers/directors/location arrangers know anything, it seems, about railways. I think they could ask for just a bit more information, but no doubt they are concentrating on the artistic side and/or the cost.
Just remembered one beautiful 'howler' - the episode of Sherlock Holmes (The Final Solution) has Holmes and Watson going by train to Dover to catch a boat. They decide to get off the train to throw Moriarty off the scent. While still on the station they hurriedly take cover as a special train comes through with Moriarty looking out of a window. The whole incident is clearly filmed on the single track of the Keighley and Worth Valley Railway at Oakworth Station; the train is the 'Old Gentleman's Coach' as used in the 1970 version of 'The Railway Children' and is hauled, I think, by an ex-GWR Pannier! The surrounding hills bear no resemblence to the Kent countryside that they are supposed to be travelling through whatsoever!
Regards,
John