Continuity mistake: They check up Pyramid Inc at the Eastpoint Insurance register for the Volvo S80 to GPS track at the beginning of the episode. Next scene they're putting a tracker on a S60. (00:01:53)
All Prologue - S2-E6
Factual error: The police "clone" the cargo dock's computer, as though it were a cell phone, so that they can watch all the cargo traffic and see when containers disappear. In reality, to "clone" a computer would simply make an exact copy of that computer's hard drive at a specific point in time. In order to see what is happening on a specific computer in real time, it is necessary to install some sort of spyware on The Target machine.
Revealing mistake: As Bunk is ordering ballistics to rush comparisons, the dead bodyguard is breathing during the scene. (00:01:55)
Misgivings - S4-E10
Other mistake: When Chris and Snoop go to kill Bug's dad, they have their high powered nail gun once again, even after previously throwing it in the marsh with the guns. Bought a new one? Not likely as the reason for throwing it away in the first place was because the cop saw it. Buying an identical one would defeat the purpose of ditching it. (00:55:50)
Unto Others - S4-E7
Character mistake: When Cutty quits the truant officer job and walks out of the office, he runs into his old girl from way back. She calls him David instead of Dennis. (00:51:00)
Other mistake: When waiting at Lake Trout to ambush Marlo, the Barksdale crew are in the same car that Marlon was driving round earlier in the series (same number plate: 107M703) It is visible as they (Avon and his crew) drive away from the scene after Chris has shot into the car. (00:51:02)
Revealing mistake: At the start, while looking over the corpse from a ground level shot, the corpse is dressed differently from the overhead shot, and is very obviously breathing. (00:01:50)
Cleaning Up - S1-E12
Continuity mistake: When Bodie and Poot shoot Wallace, blood splatters on the wall behind him. The pattern of blood is significantly different in the scene where Bunk finds his body.
Continuity mistake: In the scene where Omar walks through some alleys on his way to stick up a corner crew, he is first observed carrying a double barreled shotgun with a wooden butt. A minute later, when he emerges from the alleys and dumps the drugs down the sewer, he is seen carrying a metal pump action shotgun. (00:13:40 - 00:14:30)
Reformation - S3-E10
Visible crew/equipment: During the opening sequence when two hoodlums are walking out of the convenience store, a lighting rig and crew can be seen on the right-most part of the frame. (00:02:15)
Sentencing - S1-E13
Other mistake: Towards the end the camera focuses on three youths, one of whom the main character in the scene calls over. One of the youths appears to be Wallace. If so he made a remarkable recovery from two bullets to the head. (00:55:00)
The Target - S1-E1
Continuity mistake: As D'Angelo is talking in the foreground, a stripper in shiny lavender dress she had removed with some difficulty in the background a few moments earlier is magically clothed again as scene closes out and camera pulls back. (00:50:25 - 00:52:05)
Back Burners - S3-E7
Continuity mistake: When Poot first jumps up after Snoop rakes the corner, the blood stain his shirt has absorbed is much larger, and singular - consistent with lying in a pool of blood not coming from your body on a flat surface. When the frame changes, there are now three blood stains, each much smaller. (00:51:52 - 00:52:56)
Corner Boys - S4-E8
Revealing mistake: When Chris and Snoop are in a vacant lot getting rid of a body, the victim's eyelids move before the plastic is laid over him. (00:17:20)
Audio problem: When Carcetti is talking to the Interdenominational Ministerial Alliance, there is a moment of silence after he announces that he'll treat them fairly regardless of endorsement. During this moment of silence, the shot changes to an angle where Carcetti is mid-speech, while the audio is silent. The scene resumes in sync with the audio as soon as the shot changes. (00:47:20)
Visible crew/equipment: When Carcetti arrives to see constituents complaining about their problems, the tip of the microphone is visible in the upper left corner, as well as the man holding it. (00:37:10)
Factual error: The sailor who is interrogated at the end of the episode by the Greek gangsters is speaking Greek, not Turkish.
Revealing mistake: The guy who is supposed to be dead moves his eyes while they're closed.
Revealing mistake: The dead guy on the car blinks right before the police officer passes with the caution ribbon. (00:03:20)
Chosen answer: As he's trying on his new hat, Valchek says, with a smile, "fits like a glove!"