When Bugsy is in Jeannie's flat talking to Marty, Jeannie is sat on the sofa reading a magazine with her legs crossed, in the next shot, her legs are uncrossed and she has no magazine in her hand.
Paul Kirstner hands Jeff a glass of whisky, which he takes with his right hand and then lowers it with both hands. In the next shot, the glass is in his left hand when he drinks from it and he is then seen lowering the glass with his right hand.
In the black-and-white flashback to Bugsy's death, many of the crates in the warehouse are marked "whisky". But it's supposed to be Chicago, USA, where it ought to be spelled "whiskey".
As Jeannie gets up off her sofa, she is seen walking around Marty, as if she can see him sat on the sofa.
At 14:46 Marty says " Ask her why she's taken to sitting on the sleeping room floor " instead of sleeping on the sitting room floor.