Plot hole: Matlock figures out that The Professor wouldn't have been able to see the security guard from 50 yards without glasses, and that's what tips him off about The Conspiracy: the guard testifying that the man wasn't wearing any. However, when we see the scene happen at the beginning of the episode, the person posing as Prof. Erskine Tate is, in fact, wearing glasses. (00:04:15 - 00:22:15)
Continuity mistake: When Andy Griffith and Dick Van Dyke shake hands at the club, The Judge is holding his pipe at a different height in the separate shots. (00:24:00)
Plot hole: The forensics for this case have been quite shoddy at best, considering that Tate was drugged and not simply intoxicated (yet no toxicology test was performed) and the dog wasn't run over but repeatedly beaten with a tyre iron (which is a wildly different kind of injury). Nobody brings this sort of objection forward - the dog one would have easily destroyed the prosecution's case right away since The Professor was asleep at the wheel and not in shape to beat assault dogs up.
Continuity mistake: When Billings offers Prof. Erskine Tate a nightcap, the confetti on his shoulder changes position and quantity in the close-up on Daniel Davis. (00:03:15)
Continuity mistake: When Professor Tate congratulates Eric Lane for the improved grades, the two have a playful banter, and Tate says he's "happy to be proven wrong." Christopher McDonald has to wipe off some streamers that got in his hair. In the next close-up, he still has streamers on his shoulder despite the fact he brushed them away entirely. A similar mistake happens later on when he is carrying the unconscious professor out of the room; streamers suddenly are all over him from one shot to the next. (00:02:40)
The Affair - S1-E4
Continuity mistake: When Matlock talks to Sonia after the attempt on Rodriguez's life, Theresa Saldana plays with the wedding ring in different ways as the different angles alternate. (00:33:20)
The Affair - S1-E4
Revealing mistake: The attempt on Rodriguez's life is quite phony looking; leaving aside the trope of a person who wants to avoid being murdered by a car by trying to outrun it instead of getting out of the way (the first semi-POV of the car does a terrible job at that, since the car looks much closer to The Victim and slower than it should be, and wide room for Rodriguez to escape sideways), the impact does not happen and the stuntman jumps into a pile of garbage without anything remotely close to connecting. (00:32:00)
The Affair - S1-E4
Continuity mistake: At the Latino bar, Matlock begins playing pool to look cool with the local gang crowd - it is just as believable as it sounds. The positions of the billiard balls keep changing between shots. (00:30:00)
The Affair - S1-E4
Continuity mistake: Tyler makes his exit from the bar, switching the power off; Kene Holiday pulls the lever down, and you can see him in the darkness go past the man by him and push the door open with a clean way out. In the shot from the exterior, though, he still has to push the man out of the door and goes around him, coming out by the side of the lock instead of the hinges. (00:20:40)
The Affair - S1-E4
Continuity mistake: When Matlock is talking to Harriet and Christina Harrison Ward after his attempt at re-enacting an alternative route for the murderer, Christina defends herself, saying, "But I was asleep." Matlock answers in the reverse shot, and you can see her pose with a hand in front of her chest that wasn't raised a moment before. (00:18:30)
The Affair - S1-E4
Continuity mistake: When Matlock is interviewing the kid poolside, she just came out of the water and wraps a towel around herself without as much as touching her own head. Still, in close-ups, her hair is somewhat dry. (00:14:30)
The Affair - S1-E4
Continuity mistake: When Ben Matlock rings the doorbell of the Harrison residence, he is standing with his hands behind his back while the door is opening. In the next shot, the door is still opening, but Andy Griffith is standing with his hands by his sides. (00:08:30)
The Affair - S1-E4
Continuity mistake: The limo bringing Ben and Charlene Matlock to the fancy house in Rhode Island pulls over under an overcast sky, but Matlock steps out of the car in a brightly sunlit zone. (00:08:15)
The Affair - S1-E4
Continuity mistake: When the stepson arrives at the villa, he makes his way to the front door, shoving aside reporters. Between his POV and the next shot, the same reporters move away in different ways, with different timing. (00:03:10)
The Stripper - S1-E3
Continuity mistake: In the (deliberately poorly lit) scene where Doug's friend hurts her hand, look at the moment when she picks up the shard of glass; it goes nowhere near the area where the bandage appears later. (00:26:10)
The Stripper - S1-E3
Continuity mistake: Matlock walks by mistake inside the dressing room. Two girls with their bare backs to the camera stare back at him. We see Matlock close the door a moment later, and there's just a very much clothed girl where the two naked ladies would have been. (00:21:15)
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.