Plot hole: The resolution of the case hinges on the fact that the culprit would be compelled by The Witness (whom they bribed, but who double-crossed them) to visit their stake-out apartment to try to dispose of their bloodied clothes. However, The Witness didn't and couldn't possibly know about that apartment. The murderer tried to prevent a non-existent threat that nobody made and did not worry at all about the other, very much more likely evidence and testimony The Witness provides - if The Witness was going to trick them to begin with, it makes no sense that they didn't just record the conversation, for once. The culprit does not even contemplate that possibility.
Matlock (1986)
1 plot hole in The Judge - chronological order
Starring: Andy Griffith, Clarence Gilyard Jr., Julie Sommars, Nancy Stafford
Continuity mistake: Matlock is inside a jail cell, speaking to a man who has been accused of murder. In an outdoor scene, someone throws a raw egg at the window as Matlock looks out. Inside the cell, as Matlock turns away from the window, the splattered egg has vanished.
Trivia: Andy Griffith was the only actor to appear in all 195 episodes of the series.
The Victim - S4-E17
Question: During the trial, Matlock says that he paid a man to follow Bret which is how they were able to find the rope that Bret used. Would what Ben did to prove that Bret was the killer actually be allowed?
Answer: I did not see this episode, but YES. Both prosecution and defense lawyers use investigators to search for and uncover evidence that is legally admissible.