Audio problem: Several times during the episode, when someone is walking on a rug, the sound of footsteps is that of a hard tiled floor.
Visible crew/equipment: When the cop grabs the coffee pot, a filming crew member with blue trousers is reflected on it.
Character mistake: When the corpse is taken out of the water, he moves his mouth.
Chosen answer: This is the very reason my brother and I used to jokingly call the show, "Murder, She Caused." It's amazing she was ever on anyone's guest list for a party, given the likelihood someone would end up deceased. As to your question, most of the time, Jessica Fletcher would have had an air-tight alibi, as she was in a room full of people, or her whereabouts were accounted for when a murder occurred elsewhere. It also seems to me that there were episodes where she, purely with respect to opportunity, could have been a suspect. I believe she even acknowledged that as a logical possibility from time to time, even though she knew, of course, she was not the killer. However, the investigation would obviously rule out the possibility of her involvement, eventually.
Michael Albert