Continuity mistake: After the bad guys rough up Diamond in his apartment, his hair alternates several times between falling over his forehead and staying neatly combed as the camera angles change.
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.