Continuity mistake: Detective Hoffman is in Grey's bar when Grey serves him a drink with a cherry on a skewer. The cherry alternates between being down in the drink or up leaning on the rim of the glass.
Factual error: Almost none of the senior police officers wear the correct medal ribbons. Brian Moore and Pat Geenty wear the Order of the British Empire, which neither had. Geenty wears the General Service Medal, for military service in Northern Ireland, although he was never in the armed forces. Moore does not wear the Queen's Police Medal, which he was awarded in 2009. Both wear the Diamond Jubilee Medal in 2011, although it was not awarded until 2012. Andy Parker wears an unidentified ribbon (possibly intended to be the Queen's Police Medal, which he was awarded in 2010, but looking nothing like it) and the Golden Jubilee Medal, but does not wear the Diamond Jubilee Medal or the Police Long Service and Good Conduct Medal to which he was also entitled. Mike Veale and Ray Hayward wear no medal ribbons at all, although both would be entitled to the Golden Jubilee Medal and Police Long Service and Good Conduct Medal (and Veale also to the Diamond Jubilee Medal after 2012).
Picture's Up - S1-E5
Continuity mistake: When the detective goes to retrieve the water bottle that Zach discards into the recycle bin, he picks it up with a napkin by the top. In the next shot, he is placing the bottle in a plastic bag top first, holding the bottle with the napkin by the bottom. (00:42:00)
Continuity mistake: The mayor Bobby and Keri are talking in a restaurant. Flashback 5 years - the same man sits at two different tables in two different sequences. (00:13:35)
Most Likely to Go Your Way (And I'll Go Mine) - S1-E5
Continuity mistake: A group of people are standing before a door with full glass inserts. It has a thought processor for access. Once the group defeats the processor, they open the doors. But the doors are now solid wood, not with a glass insert. (00:29:20)
Deliberate mistake: In the restaurant after their daughter finishes talking to Niko, Erik turns the tablet device around and sets it on the table to talk to Niko. From his perspective, he is looking down at the screen. But in the other shots from Niko's perspective, where he is a life sized hologram, his figure is shown looking up and meeting her eyes. But from her perspective it should look like he's looking down at the table.
Other mistake: A Mexican pilot based in Ensenada is interviewed. He owns a 1983 Cessna 172 aircraft. When they show it in the air, it is a 2005 Cessna 182 based in San Antonio per the FAA database. A US registry aircraft would not be based in Mexico, owned by a Mexican pilot. (00:11:20)
Character mistake: At the police station when Damien Asante is reading the information on the computer about the hit and run, he says "On February 25, 2015 Christy Markus and her son were struck by a car. The driver kept going." If you look at the computer screen, the date of incident says February 25, 2018. (00:30:00)
The Graveyard of What Might Be - S1-E2
Continuity mistake: Manx has his left hand on The Wraith's hood ornament as he speaks with Bing, but when the shot cuts to Manx handing the invitation to Bing, Manx's hand is not on the ornament.
Chapter Four: Housechilling Party - S1-E4
Revealing mistake: When Ryan's iPhone vibrates with a text message from his mom, the text message is timed 5 hours before the time on the lock screen. An immediate message would normally indicate the time received as "now." (00:06:45)
Continuity mistake: Captain Dobbins has her Garrison cover tucked under the belt of her uniform overcoat with her rank insignia not displayed. In the next shots, the USMC emblem is displayed on her Garrison cover and rank insignia is displayed again. (00:25:05)
Pride Parade - S5-E3
Factual error: Nandor manages to fly up to space, then loses control and falls back to earth in a fireball as he reenters the atmosphere. But objects reentering the atmosphere only get hot because they're generally travelling at immense speeds, 7-12 kilometers per second. Nandor just floated straight up, then falls straight back down. When Felix Baumgartner parachuted from the edge of space his maximum speed was about 1,300 km/h, and he didn't catch fire.
Factual error: An FBI briefer is talking about the hijacking of a passenger airliner. He calls it Flight 6175. The airplane has 6175 stenciled on the nose. Those are usually the last four digits of the airplane serial number, used by maintenance and dispatchers to designate a particular aircraft. It is not the flight number of any given trip. (00:04:45)