When George and Rita Babtree are flying in the biplane, they are talking to each other. In an open cockpit airplane, going 120+ MPH, it would be impossible to say anything do to the amount of wind blowing around them. In a biplane you have to have a headset with a microphone to talk between pilot and passenger. Otherwise they would not hear each other over the engine noise and the wind blowing in around them.
When Reace fires two or three shots at Caldwell in the train corridor, the sound effect is that of a silenced gun. However, both before he shoots and after, he can be seen to be holding a long-barreled revolver with no silencer.
The porter claims the locomotives are not accessible from inside the train. FP7 diesels (and similar streamlined units) were equipped with access hatches in the front and rear. It is unlikely that a railroad employee who regularly works on passenger trains would not have known this.
As the train enters the station after the cars have been uncoupled, it crosses all the way to the right hand side and enters the station on the last approach track, but when it cuts to the next two shots tracks even further to the right of the train are visible.
When Grover applies shoe polish to George, the point of view over George's back clearly shows Grover touching George's forehead with the polish. But in the next shot showing George's face, there is no polish on his forehead.
When Grover (dressed as a porter) comes into Roger's stateroom to serve coffee, he pulls a revolver and initially holds it in his left hand, but in a close-up it is seen in his right and then back to his left in the next medium shot.
When Grover is crashing the stolen sheriff's car through the police barricade, long shots clearly show the stunt driver (as Grover) wearing silver-rimmed dark sunglasses. Yet, when they cut to Grover behind the wheel inside the car, he is not wearing them.
An exasperated Chief Donaldson warns the assistant controller of an impending crash at the fictional "Central Station" in Chicago - however, in several crowd shots, a sign reading "Union Station Menswear" is plainly visible.
When in the engine cab Deveroux shoots the engineer and he falls out of the cab. But later when Deveroux is shooting at the chopper, the bottom of the engineer's shirt can be seen in the driver's seat in the cab, along with a brief silhouette of a man sitting in the cab seat.
After George and Grover get back on the train the second time, there is some brief gunfire. George asks Hilly, "Are you alright?" She responds with, "Yes. What about Grover?," even though he was never actually introduced to her by name.
In the scene in which George has uncoupled the train cars, when Grover jumps, there is clear track on the other side of the train, but when George jumps there is a line of train cars on the track. In the next shot, where the camera is looking directly back to Grover, all the tracks on the right of the scene are clear.
When Deveroux is hanging out the engine the cab door is obviously open but as the train is going along the cab door is closed then at the station when the people are looking at the engine the cab door is open.
In the baggage car, the necktie Ned Beatty is wearing is burgundy with very narrow navy blue stripes. When he rushes back to Gene Wilder's compartment to recover the Rembrandt letters, his tie has suddenly changed to one where the blue stripes are noticeably wider.
The train was supposed to be traveling through the American Midwest. Filming was done in Alberta Canada and in one scene the train passes a small town with a grain elevator which is plainly marked "Alberta Wheat Pool".
The train is shown entering "Central Station" in Chicago. By 1976, Central Station had been torn down. The station used in the movie for those scenes was Chicago and North Western Station and train-shed. All the way up to the bumping post is the far West track in the old CNW station. Great shots of the old CNW-style signals are seen as well. Also, "Rockdale" is on the old Rock Island main line to the SOUTH side of Chicago, so if they had been coming in to a Chicago Station, it should have been La Salle St. Station. The only correct Chicago 'Tower" scenes were when Jerry Jarvis is on the telephone with the cop, you can see BN railroad switchers doing station work at "Union Station" in Chicago, where the "Am Road" train should have been going.
All of the night scenes of the train show saguaro cacti, which grow only in southern Arizona, even though the train supposedly passes far to the north through Flagstaff, Albuquerque, Denver and Kansas City on its way to Chicago.
This movie is presented as being set in the United States. Towards the end of the movie, the train is about to crash into the fictional "Central Station" in Chicago. When the assistant controller, Jerry Jarvis, is running through the station looking for his boss, he stops to ask a janitor who is polishing a piece of marble clearly marked "GO Transit". GO Transit is Ontario, Canada's interregional public transit system.
As the conventioneers Steve Weston, Harvey Atkin and Steve Weston pass the porters and the camera swings around to reveal Gene Wilder approaching, a billboard can be seen over the adjacent train on the left for CFTO-TV with the face of Tom Gibney, showing the location to be Toronto, not Los Angeles.
In the beginning of the movie as the train is pulling out of Los Angeles one of the city buildings in the background has a sign on it that reads "National Trust" - a company located in Calgary, Alberta, Canada.
When George is thrown from the Silver Streak, he is supposed to be somewhere in New Mexico. As he is walking the tracks, Joshua trees can be seen in the background. Joshua trees are native to the Mohave Desert region of California and some locations in Nevada and Arizona, there are no Joshua trees in New Mexico.
As the station shots were in Toronto, when Jerry Jarvis tries to find his boss, he asks someone who is scrubbing a station sign, and if you look closely, you can see GO Transit written on the sign, a Canadian commuter rail provider.
"Sweet" meets George and describes the train's route up through Nevada and into Colorado. The two states are not contiguous. Later he says the train will stop in Dodge City, Kansas which is not consistent with the route he first outlined. The Silver Streak starts out following the Union Pacific route (City of Los Angeles) and then suddenly switches to the Santa Fe route (Super Chief).
If a train actually did crash into a station and cause structural damage as the train did at the end,there is no way security and police in the station would have allowed people to approach the train after it stopped. Considering the possibility of the structural integrity of the building being compromised and diesel fuel in a damaged engine, they would have evacuated the station immediately.
Sweet, the government man, would not have further involved George in Sweet's plan to convict Devereau, as it is totally against FBI, NSA, CIA, etc., policies to directly involve innocent civilians in their operations, especially in life-or-death matters.
The morning after Prof Schreiner falls off the train outside George and Hillie's suite, the train is seen along a river and George is seen looking out the window of the third car of the eight car train but when Sweet goes on top the train to look for evidence, he only goes as far as the second car as six cars can be counted behind the car that Sweet is on.
When Caldwell is with Sheriff Chauncy, they hear the squad car coming running with sirens. Law enforcement (like other first responders) only run with lights and sirens to the scene. They would not run "hot" when transporting an apprehended suspect to custody.
When Jerry Jarvis locates his supervisor in Chicago and tells him that the Silver Streak is running without an engineer, the supervisor looks down at his watch and says that the train will arrive in four minutes. Without knowing the train's specific location at that time, and with no reason to know in advance the timetable of an out-of-control train, the supervisor would have no information with which to make that time estimate.
When George and Sweet are talking in the dining car about Sweet being a federal agent, George accidentally lights the wrong end of his cigarette (you can tell by how it flames up). He then grabs another one and lights it the correct way.
When George Caldwell asked the porter if there was another way to get to the lead locomotive other than the roof, he has another option: go through the 2nd locomotive and get to the first locomotive and stop the train, on General Motors Electo-Motive Division (GM-EMD) F units, the F7A has a door on the nose so why didn't George just go through the cab of the 2nd unit and through the engine room and go into the first locomotive to stop the train??
When George and Devereau are sitting in his compartment discussing "scenarios," the topography that passes by the windows - farmland, woodland, prairie, with or without telegraph lines - changes immediately with each cut to George or to Devereau.
As the Silver Streak is seen from a distance racing into "Chicago", you can tell the film is sped up and is not actual real-time footage. The cold Alberta air gave this away. The exhaust coming out of the locomotive is unnatural. Exhaust would be more dispersed if running at that speed, not such a long solid uniform exhaust, which would be the case if running at a low speed. Exhaust also just looks like it's coming out too fast. Most obvious time to see this would be approximately 9-10 minutes before the movie ends. Next best would be five minutes before the movie ends.
Just after George shoots Reace with the spear gun, he ends up
leaving the train by a train signal pole. When the pole swings around, the ground under George is undisturbed. In the close up, just before George drops from the signal to the ground, the ground has been disturbed where it is obvious that it has been landed on at least once before.
When George is hanging on the outside of the train, trying to uncouple the cars, long shots show the train running though yard/industrial areas - but closeups of him show what looks like open/prairie scenery behind him.
Just after George is thrown off the train, he picks up a cattle skull from the train racks. In the background of that shot you can see there is a farm house behind him with smoke coming out of the chimney, but he keeps walking for hours looking for any inhabited dwellings.
The goof items below may give away important plot points.
Before George exits the toilets at the station, he is not wearing gloves because they are still on the sink shelf and he leaves without them. When he comes to join Grover, he is now wearing the gloves and didn't have time to go back for them because the music is heard from the radio almost straight away
When Devereau is leaning out of the locomotive and about to be beheaded, in the shot of his face reacting to his impending doom, you can see that there is no track next to the Silver Streak that this oncoming train is supposedly on.
After George gets off the train for the third time and hooks up with the government agents, his part would have been completed and he would have been taken back to the main offices for interrogation and sent home. There is absolutely no way that the CIA or FBI would ever assign a civilian victim to apprehend criminals (Deverau and his crew), let alone arm him and task him with engaging enemy targets or stopping a runaway train.