Plot hole: When Carl is helping Molly out after Sam dies, he manages to find Sam's address book in a box, which he needs to launder the money at the bank. So why does he need to convince Molly to take a walk outside so Willie can break in the apartment and steal it? Carl knows which box the address book is in, and could have easily stolen it earlier when Molly was not in the apartment.
Other mistake: In the restaurant scene, when Oda Mae and Sam are trying to convince Molly of Sam's existence, Oda Mae is prompted by Sam to reply "Ditto"as Molly turns to reply, Oda Mae is about to say something else and Sam motions with his hand for her not to say anything...Oda Mae isn't supposed to be able to see Sam, so why did she stop?
Visible crew/equipment: When Carl comes and takes off his shirt, he spills coffee on himself and gets half naked. As he rubs Molly's right shoulder, the scene switches to Sam in the chair. As he leans forward if you look just to the right on the marble wall, you can see a reflection of a man with a camera, blue jeans and blue shirt. No-one else was there besides those three characters.Patrick_swayze_please_blow_me
Continuity mistake: When Oda Mae is with Lyle Ferguson, he asks her to sign a paper that closes an account. Then he gives her a another paper to sign that is yellow. When she hands it back to Lyle, it is white.
Revealing mistake: When Willy enters the apartment and heads for the stairs, Sam dives at him in anger and flies through him. In this shot you can see how poorly Willy was added into the scene. The coloration isn't even close and Willy looks 2-dimensional. (00:32:30)
Continuity mistake: In the film, Willy shoots the lock off Goldberg's door with a Walther PP but when he is looking around the flat he has a Walther PPK.