During the opening credit animation, after machine gun fire writes "Meet The Killer", the animated Costello says, "You didn't dot the 'I'!". This wouldn't be necessary, however, since the words are written in all capital letters.
After Casey and Freddie leave the body of Relia in his closet, and he rolls into the laundry cart, he lands face down. But then, when Freddie gets the cart to put Milford's body in it, he and Casey find Relia face up.
When Angela comes to visit Freddie in his suite, and they sit down on the sofa, her right arm is down near her lap. Then, when the shot shifts to the side, her arm is resting behind Freddie on the back of the sofa.
When Abernathy is looking over Freddie's shoulder during the so-called Bridge game, he starts on Freddie's right side. Then, after the camera cuts back from the close-up of Freddie's hand, Abernathy is on Freddie's left side.
Right after Freddie is about to make a phone call in the hotel room, shortly after bullets were fired through the window, the lamp on the desk wobbles twice with neither Casey nor Freddie having touched the lamp or the desk to cause it to wobble.