Revealing mistake: When the episode ends and Jessica drives the buggy, she is replaced by a very obvious stunt double with a wig that not only does not resemble her hairstyle, but it's grey as opposed to her light blonde colour.
Murder, She Wrote (1984)
1 mistake in A Nest of Vipers - chronological order
Trivia: Angela Lansbury is the only actress to appear in all 264 episodes of the show.
No Accounting for Murder - S3-E19
Question: Why did the Phantom run out of nowhere after tying up the killer when Grady came into the room with Jessica? Did the Phantom try to avoid being seen by others except Jessica?
Answer: Yes, he didn't want to be a hero. He liked being the Phantom going anywhere and doing what he pleases with people thinking there was a ghost.