Continuity mistake: When Gayleen looks at Speed gamble away his winnings, her hand is on, then off the table. (00:56:50)
Continuity mistake: Speed has the loan shark at his neck. The night after they damage his car, he is waiting Poe and Chaney at the dock. There is a car behind him, and the people by the vehicle change between shots. (01:04:05)
Continuity mistake: Chaney walks away from Street, Gandil and Jim Henry turning down the fight offer; the balls on the billiard table change positions between shot and reverse angle. (01:10:35)
Continuity mistake: Before the final fight, the bad guys come out of the room at the top of the oyster plant office building. They release Speed and he walks towards the stairs. The evil enforcer Street comes out of the door in the first shot, walks a few steps, then in the next wider angle we see Speed walking down the stairs but Street is still inside and comes out only a moment later. (01:20:35)
Continuity mistake: When Speed tells Gandil that he's always going to smell like fish, the moustached henchman in the background is holding the coat with one arm, but at the cut he is holding it over both crossed arms. (01:21:50)
Continuity mistake: During the final fight between Street and Chaney, Chaney's shirt rests on the car's front in different ways between shots; you can tell for instance when they struggle by the car (a moment before the shot when Speed yanks Poe out of the way). The shirt shows its buttons; a minute later they are back fighting by the car and the shirt is folded the other way. (01:24:45 - 01:25:40)
Visible crew/equipment: In the fight with Street, Chaney gets knocked down by a double axhandle to the back. When he gets up in close-up to tackle Street, a shadow cast on the wall (probably camera equipment) moves independently of him and does not appear in the other shots. (01:25:25)
Factual error: As the protagonists say goodbye at the end of the movie, Speed pulls over in a railroad deposit. The wagon he stops by shows an odd graffiti. Upon further inspection, you can tell that it's actually an attempt to conceal the giant logo (the so called "split rail" logo) of the Illinois Central Railroad, a logo used by the company between 1966 and 1972, way after the period the movie is set, in the 30s, when the logo would have been the green and yellow diamond one. (01:28:30)
Continuity mistake: When Chaney takes care of the 'in-betweens' at the end of the movie, the light is different in the separate angles with James Coburn holding the money, and so is the angle the bills are tilted at. (01:29:20)
Factual error: When Chaney shoots towards the bar counter, the bar sports a calendar that shows exactly 29 days in the month. The only possible month with 29 days the first being on a Sunday would be February of the leap year 1930, but the movie is set post-prohibition. The scene is not set in February anyway - minutes later they show up at Lucy's home at 5 am and the sun shines.