Continuity mistake: Diamond returns to the all-night cafe and parks with his car pointing toward the door. After he goes in and comes back out, the car is in a completely different position, parked parallel. (00:10:20 - 00:11:30)
The Case of the Borrowed Baby - S5-E26
Continuity mistake: Mason takes the medallion back from the matriarch as he leaves her home. A little later the old lady shows up at Della's and shows the medallion to Della.