Factual error: When John Smith spins the J&B bottle in the middle of the road at the beginning, it stops showing the stippling on the bottom. Stippling wasn't invented until 1940, and the movie takes place during the Prohibition era. (00:02:35)
Continuity mistake: John Smith's guns can hold about six dozen bullets apiece.
Continuity mistake: Before John Smith shoots the man above the skylight in the hotel, he reloads his two pistols. When he shoots the man, he only fires the gun in his right hand. In the next shot, we see two empty magazines fall to the ground as he reloads again.
Other mistake: Shooting two forty-fives at once is hard. Willis must think so too. One gun fires blanks and the other gun operates like a real pistol, even emptying out shells, but is not firing. This is very noticable in slow motion during his first standoff.
Other mistake: Upon entering the bar to rescue the bartender, Willis shoots his first victim clean through a window. In slow motion you can see the gun is never fired and yellow flash is edited in.
Factual error: When Smith shoots the first man with his twin .45s, the man flies back about 30-40 feet. In reality, he might fall back a foot or two, but he certainly wouldn't be propelled anywhere by simple bullets.
Factual error: The phones in town are crank type or candlestick type that require an operator,as mentioned by the hotel owner at the beginning of the film.John Smith calls Georgio at the telephone office by dialing the number,impossible on a system with no central office switching equipment.He would have just used the patch cords and pressed a button to ring the phone.