Visible crew/equipment: When the officers are practising with the riot gear, the reflections of the studio lights are frequently seen in the shields.
Continuity mistake: The packages Drake and Kathy place on the table beside their coats have disappeared when they return for the coats a few shots later. (00:19:00 - 00:21:20)
The Best Years of Your Death - S1-E3
Plot hole: In the chapel, you can see the heads of those who tried to cross Harriet (the mad matron) preserved in formaldehyde. How did she get hold of so much of it? Wouldn't her husband or the headmaster be suspicious?
Coming Home - S3-E6
Continuity mistake: Andy and Swarek pull up to the scene of an illegal party and turn off their cruiser's flashing lights - twice.
Other mistake: When Jessica calls Hondo to let him know about Deacon's wife, you see Hondo answer the phone normally. Right after she tells him what's up, you can see him holding the phone upside down, with the camera lens towards the bottom. (00:24:30)
Who Killed Avery Lord? - S1-E23
Visible crew/equipment: After the woman in the negligeé goes back into her apartment, a crew member's shadow appears on the corridor wall. (00:42:00)
End Game (1) - S8-E7
Revealing mistake: Boyd has a video-conversation with Linda on the phone she sent him. On top of the screen you can see how long the video will last (1 minute and 3 seconds), showing it's a pre-recorded video, not an actual live conversation.
Factual error: At the end of episode 6, we see Alain crossing the German French border in a European registered right-hand drive Citroen CX. Then at the very beginning of Episode 7, they check into a hotel and the Mercedes parked in the forecourt was also right-hand drive. (00:01:00 - 00:01:30)
Continuity mistake: Gandia dislocates his right hand thumb/wrist to free his right hand from the handcuff as shown from the back but the next shot shows a free left hand instead.
Audio problem: When detective Bryant gets rough while interrogating the suspect of the shooting he tells him to sit down. When we cut to a different angle we hear him repeat the last few words of his sentence.
Continuity mistake: In the morning, Annie comes into the kitchen and says hi to her niece and nephew. Her jacket is alternately buttoned or unbuttoned. (00:39:30)
Factual error: The show has a BMW X5 (2007 - 2012) appearing when the media goes to the brother's house. (00:27:50)
Episode #1.7 - S1-E7
Factual error: When Marie is talking with her therapist, she talks about having just gone to see Zombieland. Given that the scene takes place in 2008 and Zombieland wasn't released in the US until October 2009, this simply is not possible.
Suggested correction: The series starts in 2008, but it's 3 years later. At the beginning, RoseMarie says Curtis was born February 3, 1981 and is 30 years old.
The therapy scenes are in 2008. It's only when the photographs of Marie are discovered that we see Marie 3 years later, in episode 8.
Revealing mistake: Episode 15, "Faceoff": When the agent fires the hook to get to the roof of the church, it does not reach the balcony. However in a following shot you can see the agent climbing there. (00:10:05)
The Two Deaths of Jamie B. - S2-E4
Revealing mistake: When Naomi shows Kirsten the money, you can tell it's fake. Not only are the serial numbers all the same, you can read "this note is not real it is to be used for motion pictures."
Continuity mistake: As Banacek approaches the room in the farmhouse that has the cross, he has a cigar in his mouth. As he enters, the cigar is gone.
Factual error: Chief Superintendent Hilton wears the ribbons of the General Service Medal (awarded for military service in a combat zone, most commonly in Northern Ireland) and the Police Long Service and Good Conduct Medal (awarded for twenty years' service), but not the Golden Jubilee Medal (awarded to all officers with five years' service in 2002), which he would also have. When he reappears in Series 4, he is wearing the Golden Jubilee Medal, Diamond Jubilee Medal (awarded in 2012) and Police Long Service and Good Conduct Medal, which would all be correct, but no longer has the General Service Medal.
The Blessing of Many Fractures - S1-E8
Continuity mistake: During the fight with Zhou Cheng, Cheng does a forward flip and kicks Danny, making him stumble backwards. In the shot of Cheng lying on the ground, Danny is holding his stomach. In the shot immediately afterwards, he's holding his chest.
Character mistake: The registration number of Alan Salt's car is HUA222B, but when Rachel is on the phone asking an officer to look up the car's registered owner she gives the registration number as B222HUA.
What They Saw in Southie High - S1-E2
Other mistake: Agent Rohr asks who the cold case is related to. A dossier is given to him and the front cover contains a photograph and the name "Kanicki, K". Agent Rohr says "Kelly Kanicki" but there was no indication of the full name, just the initial. (00:08:30 - 00:09:00)