Santa Claus - S1-E12
Visible crew/equipment: When Mark Harris shows Matlock into his office, the actors' three tape marks (one T-mark) are visible on the carpet behind the chair, and at the bottom of the screen.
The Stripper - S1-E3
Continuity mistake: When Ben and Charlene Matlock visit the precinct and give The Gift to the proud new daddy, Ben teases him, saying that it's so that the boy will dress better than his father. The guy acknowledges the joke, pointing at Matlock in a friendly way. Nothing in his hand, then all of a sudden he is holding a cigar. (00:06:00)
Diary of a Perfect Murder - S1-E1
Continuity mistake: Matlock questions Mrs. Harris at the stand; Andy Griffith keeps switching between a hand in his pants pocket and a hand on the jacket over his hip. (01:06:40)
Answer: If it was ever found out that she was at Terry's house before he was killed, there's a possibility that a lot of people would have begun to suspect her of murdering Terry. By claiming that she wasn't, she was hoping that people wouldn't accuse her of the murder.