During and after the fistfight, West's shirt goes from wet to dry to wet to dry; and torn to not torn to torn to not torn several times. Also, the tear in the shirt moves from down near his waist to up near his shoulder and back.
The key fob West finds is from "Moriarity's" but the sign above the establishment is spelled "Moriarty." The mayor pronounces it "Moriarity" but the sign on the back of the building is spelled "Moriarty." The office window is spelled "Moriarty" but Jim pronounces it "Moriarity." Moriarity pronounces his own name as "Moriarity" and Arte does as well. The end credits has it listed as "Moriarity."
When Jim escapes from the box on the bottom of the body of water, he comes up in a cloud of bubbles clearly illuminated by daylight. But the scene takes place in the dark at night, and when he reaches the surface of the water, it is dark.
The prize fighter drops a slug that he had been using while fighting Jim. The camera zeros in on the slug, then goes to Jim's face (to show his displeasure that his opponent was fighting dirty). The camera then returns to the ring and both men. But in these frames the slug is now gone having apparently vanished into thin air.
When the assault wagon blows up, the blast comes not from the wagon but from the ground surrounding the wagon (obviously where the pyrotechnics crew had placed the charges).
When Jim shoots the Sheriff, the Sheriff falls out of the bell tower and on to the street. But when the Sheriff falls, he quite obviously jumps outward to thrust himself out in order to clear the wider part of the structure immediately below the bell tower.
After Jim has shot the Sheriff, as he walks away, he casts two shadows in the daylight. Several other towns-folks then cross this street scene with each one casting two shadows as well.
In the beginning sequence, West is seen speaking to the Sheriff with a one-gun belt or rig around his waste. As West chases the bank-robbing wagon he is seen running and firing only one handgun. He stops to take cover behind a barrel and is mysteriously seen firing two guns that eventually run out of bullets. He then runs behind the wagon carrying only one gun again that is used to shoot and kill one of the bank robbers.
He picked another pistol that had been dropped.
The bad guys are plotting their next caper. But they are all wearing their hoods. Why would these men want to conceal their identity from each other? Further, the Sheriff knows who each man is, addressing them by their names. But they are all dressed exactly alike, so he has no way to differentiate them. It is an odd scene to say the least.
After Jim is knocked out he is laying face up. After the opening credits,he is face down.
While standing at the bar, Robert Conrad refers to Ross Martin as Arte, after being introduced to him as Ned Buntline.