When Archie straddles the car over the train tracks in order to stop the train, he panics because it looks like the train is not going to stop in time. The train stops just as the trains bumper nudges the car bumper. However, When Richie starts to drive the train away, the train has to travel some distance before it actually makes contact with the car it was previously already touching.
Constantly changing sun and shadows throughout the train chase scene. Especially noticeable then they decouple the train cars (sun high and from the side), and Archie taunts Yablonski (sun lower and directly from behind).
Leon B. Little falls down a manhole, up to his knees in "guck", apparently in a sewer. But when he gets out from "the Tunnel of Love", he emerges from the mouth of the abandoned Pacific Electric trolley car Subway.
When Archie flags the train, it stops with the engine's drive rods near their highest point on the wheels. But when the train starts to move again, the rods are down close to the ground.
When Harry Doyle stands under a tree to hear a bird sing, the bird is a mourning dove. Doves and pigeons never sing.
The locomotive used in the filming is Southern Pacific GS4 #4449, owned by the City of Portland, Oregon. On the locomotive's skirting above the pistons, the word "Daylight" is visible in a shot. When the locomotive was wrecked at the end of the movie, the words "Southern Pacific" are visible. The "Daylight" was an SP train from the 1940's for which the locomotive was built. However, throughout the film the train is called the "Gold Coast Flyer," and SP had no such train.
It is stated multiple times in the film that Harry and Archie have been paroled from prison after thirty years for robbing a train in the mid-1950s. However, the newspaper headlines seen in the film state that their sentence for the robbery was thirty years. Harry and Archie wouldn't be on parole if they've already served their full sentence.
The exterior shots of Mickey's show the doors opening outward while the interior shots show them opening inward. The hinges are standard 'saloon bar' hinges seen in every cowboy movie that features a saloon, and work both ways.
Belle tells Harry at the retirement home her room is 321. But later on, when Leon and Richie come to the home, the number on the door is different because this is Harry's room, and she happened to be there when they arrived expecting to find him.
When Archie goes to the Gym he gets on some sort of weight machine where he pushes a bar down - when he lets it go it bashes him on the chin but you can clearly see it stops short about six inches away from his chin.
When Archie is in the clothing store he mentions his date wants him to look hot and suggest blue before the clerk, Derek, says red is hot. Archie then requests red but tries on a blue outfit first and then a few other non-red outfits for some reason before finally choosing a red one.