A Deadly Net - S2-E2
Plot hole: S2E2 A Deadly Net Midway through the episode, Sylvia and others in the cast bid people goodnight, offer after-dinner drinks, but the sun is shining brightly and continues to do so for quite a period of time as events continue to unfold.
Episode #4.1 - S4-E1
Plot hole: When DCI Roz Huntley kills Forensic Coordinator Tim Ifield the crucial piece of damning evidence is her DNA under his fingernails after scratching her arm. Problem being, at the time of his murder, he was wearing surgical gloves. (00:56:40)
A Scooby-Doo Valentine - S3-E3
Plot hole: It's never explained how JC Chasez and the Hollywood extras impersonating the gang gained the super strength they possessed to do things like ripping car roofs open or holding up the Mystery Machine.
Plot hole: After Jack's wife disappears for a couple of days, he receives a call from her cell phone from the cab driver who found it. Jack arranges to pick it up from a hotel. After he picks up the phone, its battery dies as he checks it, at 12:13pm. In the next scene with Jack, he's in a bar with the phone plugged into a charger; when it comes on, he checks it - the battery shows 3%, but the time is 9:13pm. He apparently wasted 9 hours when he's in pursuit of his wife's mysterious disappearance before plugging in the phone. A scene later, the time is now just a minute later at 9:14pm but the battery is now charged to 79%. (00:37:25 - 00:40:45)
Farewell My Beloved Witch - S1-E3
Plot hole: Lupin was captured by chance, and he did not plan for that, nor he seemed to have previous knowledge of Stern's appearance, but he escapes regardless using a Mission Impossible-like perfect mask of him. He also somehow kept his own blazer, tie and shoes underneath the uniform and boots he stole and wore. (00:16:00)
The Assassin - S6-E8
Plot hole: There's no way Shelley Hack could clean up all that mess of blood and three dead assassins with only an hour or so before her dinner party.
Plot hole: The poison is in the dog collar. Anson gets the poison from touching the collar. Why didn't the dog get any poison from the collar?
Suggested correction: The poison cannot penetrate the skin as dogs don't have sweat glands on their bodies (except on the paws).
Episode #1.3 - S1-E3
Plot hole: The killer is meant to create the perfect crime, but the angle of the shot would make obvious to any forensics examiner that it's a suicide. There is practically no possibility for a person supposedly positioned across a long dining table to kill someone else with a shot under the chin. (00:55:50)
The Death March of Young Kindaichi File 3 - S2-E3
Plot hole: Kindaichi bases his solution on a fact (there was a certain object on the elevator together with the victim) he couldn't know about, since Li did not mention it (and if he did, he would have been on the right track to solve the mystery himself).
Plot hole: When Nadia had been held captive in The Village, how did she get word to her accomplice to be ready at the exact time, in the exact location, and with a packing crate ready, and a whole series of transports arranged? Even if Nadia was in on the ruse of conning Number 6, wouldn't he be suspicious?
Plot hole: The bad guy somehow knows what is going to happen (via the sketches) even though the events haven't happened yet, like knowing Mrs Peel was going to show up at Pool's mansion in that catsuit and hat, and that the scenes were going to play out like the sketches.
The Case of the Deadly Toy - S2-E27
Plot hole: Claire Allison spends the night in an upstairs bedroom in the Jennings' home. In the middle of the night, she opens a walk-in closet to get another blanket and finds a small printing press. Later in the day, Claire returns to the home, accompanied by Perry Mason, who tells Mr. Jennings that Claire has received threatening letters from Mrs. Jennings' former husband, who still has a key to the Jennings' home, and the printing press may have been used to address the envelopes. Mr. Jennings says, "We'd better investigate" and immediately goes upstairs and opens the closet, even though neither Claire nor Perry Mason said where Claire saw the printing press.