When Corky kicks the gun out of Caesar's hand, she is wearing socks, having removed her paint-stained boots. But as she follows through with the kick, she is wearing boots.
When Ceasar is insulting Johnnie's corpse, Johnnie blinks.
When Corky is fixing the sink, Violet's legs are visible, and they change from black hose to no (or nude) hose then back between shots.
When Corky drinks coffee there is one tattooed triangle on her right hand. When she is opening the case there are two. When she dumps the money in the paint there is one again.
When Caesar finds Violet with the telephone in her hand, she is wearing a leather jacket. When he throws her on the bed she is not wearing the jacket. When she stands up it is back on again.
The cleaning of the money -- washing, hanging up to dry, and ironing -- could not possibly be accomplished in one night. $2 million in 100-dollar bills is 20,000 individual bills. Even if each one was handled for only 10 seconds, it would take more than two days of constant work.
When Gino talks to Caesar and Johnnie, he asks if they 'cameesh,' that is, if they understand. The correct expression is 'capisce' or 'capeesh' for the verb form 'capisci' from the Neopolitan dialect of Italian.
The blood (from Shelley's murder) on Caesar's shirt is bright red; it should be dry and dark by the time he gets back home.
When Corky goes after Caesar with the wrench, her hands are clean despite having carried the two bags of money which were covered in white paint.
Caesar grunts slightly after he has opened the paint can.
The end credits correctly spell "Caesar's stand-in" but in the cast list, they misspell the name as "Ceasar."
In the standard format home version, when Caesar first comes home and meets Corky, you can see Corky's "mark" on the floor. Even in the widescreen format, you can see her look down at it before she stands at her place for the scene.
When the cops enter the apartment they would smell the smoke from two guns and several rounds of ammunition having been fired even though the smoke should have cleared after the window had been opened and closed.