Plot hole: To identify the owner of a severed leg, Pride asks Loretta if she can guesstimate the body's general build by the foot's boot size. A much simpler way would be to swab for blood where the leg was severed and run it through the military DNA database.
Plot hole: A major plot device is Harry's fingerprints on a whisky glass at the murder scene. We see the glass being taken after he drinks from it at a bar. Why are there only his prints on it and not the bar staffs'? And why does no-one wonder why the victims prints aren't on it as well? If they think it is an attempt to frame him, why do they not even check if it matches any other glasses in the apartment or is an odd one out?
Plot hole: Although William Lewis burns his fingertips in an attempt to avoid identification, the Special Victims Unit could have identified him early on by examining the remaining unburned area of Lewis' hands, and in good police procedure still record the newly scarred fingerprints, as these new scars actually make his fingerprints more unique. His scarred fingerprints would still be at Alice's apartment crime scene, and during the trial at the end of the episode the prosecution would still have a strong argument for placing Lewis at Alice's apartment, even if the DNA evidence is thrown out because of alleged cross contamination.
Plot hole: When the watch is sucked to the island by the magnet, where was the sailor that the watch was attached to?
Plot hole: Jamie and his witness are in a patrol car when they are attacked by criminals in a van firing machine guns at them. Jamie (of course) chases them away after a prolonged firefight, and when the van is driving away we see another patrol car also shooting at the fleeing suspects. There didn't appear to be any cars with Jamie, nor did anyone come to his aid during the gunfight, and this other patrol car was facing the wrong direction.
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 Countess - S1-E4
Plot hole: Rockford and Carl Brego are punching and kicking each other on the beach. Someone shoots him down with a rifle. The INSTANT Rockford goes to check out if he's still breathing, two people randomly happen to walk on him popping over from behind a rock as they were having a super casual and amused chat, but see Rockford by the shirtless brute and make a horrified face. Later in the episode the two identify Rockford and say that it looked like the two were fighting. Their facial expressions at the time don't make sense as depicted. Even if we assume that they did not see anything at all and they played it up/filled the blanks in their mind later, the two are not deaf and yet they were not perturbed or curious in the slightest after the loud bang of a gunshot. The way the scene was shot, the only thing tipping them off about anything was seeing Rockford over the corpse (which had barely a small dot of blood visible at the time and would hardly tip anyone off at first sight). (00:18:45)
Plot hole: The mysterious neurosurgeon Dr. Quinn was mentioned by the fake Myles Taggart under the pretence that his presence was announced by the local newspaper. It turns out that his invitation by the university was a lie - presumably no newspaper story existed at all then, or the university would have acted on that. Taggart is exposed as a fraud, Quinn's link to him is so direct that he was even the one who invited him (instead of goading the Colonel into inviting him like it was his own idea) and yet the Colonel continues to trust Quinn blindly - he even has the whole night and day to think about this simple fact, nothing was decided on the spur of the moment.
The Man They Called a Magician - S1-E2
Plot hole: Lupin was knocked out by Pycal when he shot him with a gun at point-blank. On the other hand, the 'shield' he used was strong enough to not even budge when Jigen's gun and several machine-gun shots would hit, and sustained the impact of an anti-tank rocket, so the dampening powers of the chemical are pretty inconsistent. It's also completely impossible that it works as shown, unless it also coats the mouth, the nostrils, the eyes.
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.
Plot hole: Episode 1: All passengers on cruise ships have a passenger card with their name and cabin number imprinted. They are not just identical key cards like in hotels.
Plot hole: During Ryder's report, as Bruce and company watch it on TV, the camera suddenly zooms in on Joker standing on a catwalk above Ryder, and none of the crew, especially not the camera man who caught the villain, makes a comment about this. They may have thought the Joker (or rather an impersonator) was perhaps a surprise gag in the show, but since this is supposed to be a serious documentary report, it is still strange that they wouldn't point it out.
Plot hole: When Mike Walker is out looking for his son Connor calls Satch and asks, "What's up with Mike?". She couldn't know that there was anything up with him, she left before he heard his son was missing. Had she called Walker on his cell, he would have explained what was going on, as he was very eager to tell her. Obviously a set-up so that Satch could tell her that the boy was missing.
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)
Second Sight - S4-E7
Plot hole: Kimble enters the bar in the midst of a fight between photographer Howie and a man he tried to blackmail. Kimble comes in too late to hear what the scuffle is about, yet after breaking it up, he somehow knows all about the incriminating photo that sparked it. (00:06:00)
Woman in the White Hat - S2-E4
Plot hole: Ronnie and her daughter, and son-in-law spot a pick-up truck towing a large trailer through her plantation. Ronnie runs to her truck to investigate. When she arrives, which could only be a few minutes behind the truck and trailer, there are technicians well into the process of mixing chemicals.
Plot hole: It's revealed that the gym owned by Ray and Terry is a front for Ray to launder his income. This is why he doesn't want or can't sell it. Any person auditing that gym would know it doesn't bring enough income if the floors are in disrepair and the equipments garbage as Terry tells Pie when he gives him money to fix it up after Mickey pays him. Ray runs a consulting firm, he could launder millions through consulting, he has an office with employees. Get vending machines, anything that's cash. (00:42:00 - 00:44:20)
Deathfist 5: Major Crimes Unit - S2-E15
Plot hole: The whole case is solved because of astronomical coincidences, since the culprit is someone related to the actor, who is teaming up with the investigators for an entirely unrelated reason. Los Angeles is kinda too big for this sort of 'coincidence'. Moreover, had they committed the crime any other day (there was no particular reason) there would have been no connection.