Continuity mistake: When the movie begins, Constance's hair is falling loose on her face when she is about to take the picture. When she stands up, it's fixed and only a loose strand of hair falls. This changes back and forth.
Continuity mistake: When Gus March-Phillips is being recruited, Gus helps himself to whisky then grabs some cigars from a cigar box. The cigar box is easily identifiable as a Fuente Fuente Opus X brand, made by Arturo Fuente. Opus X cigars were first produced in November 1995.
Continuity mistake: When the milkman is drinking milk in the bar and talking to the Tony the Tiger actor, the amount of milk in his glass changes with the different camera angles. It goes from 2/3 full to mostly full to half full back to mostly full. (00:54:56 - 00:55:45)
Continuity mistake: During the robbery at the convenience store, Marcus raises his left wrist and looks at his watch. A shot later, his hand is lowered.
Continuity mistake: When Lagrange finishes dancing with Argylle, she places both hands around his back, the left over the right. A shot later, they're placed the opposite way. (00:02:10)