Continuity mistake: Before Tony leaves he closes the drapes. He then says he won't go out and will stay home. She says to go out, and he agrees, so he goes to the drapes and closes them again.
Continuity mistake: There's an oscillating fan near the ceiling that alternates between running and not running from one cut to another in one scene.
Continuity mistake: When Johnny Friendly is threatening Charlie about keeping Terry from testifying, they are seated at a table across from each other. There is a bottle of alcohol in front of Charlie. In most of the scenes of Charlie behind the bottle, the label can be seen in full. In a couple of scenes, the bottle is turned to the right and only shows a partial label. Charlie was obviously not handling the bottle.
Visible crew/equipment: In the opening scene, Edmund O'Brien grabs a bookie, drags him down an alley, and around a corner. When they round the corner, the entire boom and mic cast a huge shadow against a stark white wall.
Continuity mistake: After the operation to change Vic Brady's face, the first time the bandages come off, the scar on his forehead runs diagonal from the top of his nose to well above the eye. However when he's shot by the pool, the scar runs laterally across the middle of his forehead.
Continuity mistake: At one point bus driver Frankie Howard shins up a signpost to read road directions in the fog. The sign says WET PAINT and he slides down with his uniform jacket streaked and ruined. However, several minutes earlier, as he leans forward to peer into the night, Howard is already wearing the paint-stained jacket.