When Lelia answers Tom's call, she hangs her headphones on the microphone stand, but after the shot of Tom the camera shows the mike stand again and the headphones are gone.
Locomotive engineer's position is on right side of locomotive cab, not the left.
When Eleanor is playing chess against the self proclaimed "Grand Chess Master", her opening move is illegal, moving her pawn from C2 diagonally to D3. It's not as obvious when she's initially shown moving the pawn, but immediately after there's an overhead view where it's visible.
On the station platform in La Junta, the two passenger cars in the background are actually self-propelled Rail Diesel Cars, which would not be used as coaches in a passenger train.
The external train shots constantly show incorrect trains. One shot they show the Acela Express and this is clealry not an Acela.
Amtrak does not offer continuous service between Washington DC and California and there are no train routes resembling the one seen in the film. The interior of the train also in no way resembles an Amtrak sleeper train, of which there are actually none in service between Chicago and Washington, DC (riders must transfer to a different type of train in Chicago to continue overnight through the Midwest).
Tom and Higgins are talking at the last stop before entering the mountains. Higgins says there is a storm coming. Tom says he noticed that they added another diesel locomotive. And at the end of the movie you can see a real train in the background with two diesel locomotives, both headed forward. However, when the Christmas Train is trapped on the mountain in the snow, all shots of that train, probably a model clearly show only one locomotive.
That is not an Amtrak train. Nothing about the interiors even resemble the inside of an Amtrak train.
The first aerial shot of a city skyline outside of Washington D.C., incorrectly labels the city as Toledo, OH, when it is clearly the city of Cleveland, OH.
When the train stops in La Junta, Colorado, they can clearly see Pikes Peak from the train station platform. But anybody who has ever actually been to La Junta knows that you can barely see ANY of the Rocky Mountains from that small town in the southeastern portion of the state, which is flat as a board.
The Christmas Train made a stop in Chicago, presumably at Union Station. However outside the train station the address is incorrectly labeled on the building. It is shown as "1150". The train station filming location in the credits is listed as "Pacific Central Station", Which is located at 1150 Station St, Vancouver, BC.
The train they would be on to Los Angeles would be the Southwest Chief. The Southwest Chief does not go through the Colorado mountains. It goes south from La Junta, Co to New Mexico, through Arizona to LA.