The militia troopers wear distinctive green uniforms with black hats. During the wagon chase scene, rather than shooting the scene with the militia troopers, stock footage from another TV show or film of galloping US cavalrymen is inserted. Also, there are 8 or 9 troopers in the long shots, but after West and Gordon jump from the wagon, there are only four following it.
West's hairstyle varies from scene to scene, between the usual erect style and Robert Conrad's own shorter natural style.
In the wagon chase scene at the end of Act I and beginning of Act II, the wagon West and Gordon are riding in is being pulled by a team of FOUR horses in the shots before the end of Act I. At the beginning of Act II, before they jump out of the wagon, the wagon is being pulled by TWO horses.
During the opening sequence, West exits the attic room by sprinkling a white powder in a circle, which subsequently ignites and burns through the wood floor. Note that the circle of powder changes from a small-diameter circular shape during the close-up to a larger irregular shape more like a square in the long shot when it ignites.
When Jim pulls Arty (as Addison) out of the body drawer in the morgue, he takes Arty's disguise off by pulling off his wig, then a full facial mask. But later after Jim's trial, Arty "unmasks" himself by pulling off his prosthetic nose, mustache, sideburns/beard, bushy eyebrows, and wig, instead of a full facial mask.
After the trial, in the courtroom/hotel lobby, the first bad guy that attacks West is slammed against one wall that meets the side wall at an angle, then through a door in the first wall. When the guy is slammed against the wall, the whole wall moves, showing there was no joint between the two walls - showing that the wall he was slammed against was just a temporary wall anyway.
In the morgue, Artemus says to Jim "I'll give it the old college try." The phrase "Old college try" first appeared in 1918, more than forty years after the time frame of the series, 1869-1877.
When Montgomery is near the end of his passionate speech in the final scenes his scar is starting melt showing it is just make up.
Right at the end of act III, The steel door that traps them is still partially open. You can see the sunlight as the frame freezes into the drawing.
In the scene when Jim and Arty are making their escape, the night time sky is blue. Obviously, the director was using a filter to darken the scene, but this style only darkens the blue sky. It cannot and does not make the sky black, which is how the night sky looks.
After Jim's trial and after Arty has assumed a new disguise and exited the courtroom, Jim is attacked. At one point he punches his assailant. The blow from Jim's punch "knocks" Jim's assailant back against the wall, and the wall moves back, revealing that it is rigged to absorb the blow of someone's body hitting it (much the way a shock-absorber softens a blow).
After Jim's trial and after Arty has assumed a new disguise and exited the courtroom), Jim is attacked. At one point he punches his assailant. The blow from Jim's punch "knocks" Jim's assailant back against the wall, and the wall goes back (like a shock absorber). This "shock absorber" then actually rebounds Jim's assailant, throwing him, momentarily, back toward Jim. Jim's assailant then stops this "rebound" and throws his body back against the wall. So, with one blow, Jim's punch actually knocks his assailant back twice.
In the opening scene, right after Jim has shot the man on the gallows, one of the militiamen fans his gun up at where Jim is located. He is at first to the side of the man in the derby, but then takes a step back so that he is now behind the derby. He fires once more from this position, and when he does, the muzzle of his pistol is beside the derby's left ear. As he fires, derby visibly winces from the report of the pistol.
The crowd they show at the rally is NOT the one they show as the supporters leave in uninterested fashion. The big crowd rally shots are not used in the final minutes of the scene. It's a noticeable difference in the number of patrons.
In the opening scene, as Artemis is dragged to the gallows, Montgomery asks him to tell the name of the one who sent him there. Artemis mumbles, and if you listen closely, you can hear a single yell followed by a hammer-like bang in the far distance.
The sound of modern Velcro is heard tearing apart when Artie is changing between disguises.
When West first serves the warrant on the Governor, the shadow of the camera can be seen crossing the back of Captain Dansby.
In the opening scene, as Jim is trying to elude the manhunt for him, the film crew is obviously using a Sun reflector shield to "spotlight" Jim. As a militiaman crosses the scene with a house, the Sun "spotlight" moves up onto the brick wall of its veranda, spotlighting where Jim emerges from behind a hedge. Then as Jim trots toward the camera, the Sun "spotlight" moves down off the wall and onto the grass to where Jim runs. Jim then ducks behind a bush on the right of the scene as two more militiamen run by him and the Sun "spotlight" moves to the bottom of the scene, then off camera. The Sun "spotlight" next reemerges back to the bottom of the scene to light up Jim as he reemerges from behind the bush. BUT as Jim does reemerge from behind the bush and moves to the left, he runs by the Sun "spotlight" and ends up not being spotlighted by.
When West and Gordon use the tunnel to arrest the Governor, the explosions in the tunnel that were supposed to kill them apparently block it off, as Gordon says, "Well, there goes that as an exit." Yet, after arresting the Governor, they leave the mansion through the tunnel.
Jim and Arty make their way to the Governor's office via the tunnel. But Brubaker and Montgomery know that Jim knows about the tunnel and have rigged it to blow up and kill the Secret Service agents. After the tunnel is blown up, it is filled with rubble and Arty says "Well, there goes that exit." They then go through the secret door to the Governor's office and after arresting Brubaker go back through the secret door to the tunnel. There they successfully escape back to the street, even though moments earlier the tunnel had been obstructed with rubble.
Jim and Arty get Brubaker to their train, where Montgomery (gun in hand) gets the drop on them. Dansbury and his men arrive, but none of the militiamen have their guns in their hands. Montgomery tells Dansbury to kill Jim and Arty after he leaves with Brubaker. Dansbury assures Montgomery that Jim and Arty will be killed when his men have accidents cleaning their guns. But even though Jim and Arty are to be "accidently" killed as the militiamen are "cleaning their guns," NO ONE still has their guns out and on Jim and Arty. Consequently (and NOT surprisingly) immediately after Montgomery takes Brubaker away, Jim and Arty attack and beat up the militiamen (who are still just standing around). Thusly, Jim and Arty are able to once again save the day.
When Jim knocks out the morgue attendant and puts him in a body drawer, you can see the attendant shift himself to fit better.