Revealing mistake: In most episodes of the season, the computers at the station lack the power cable. It might make sense in the very first episode when it is mentioned that they aren't in a working state, but under Richard's guidance they routinely use it afterwards. For instance in episode 3 Camille during Tom Hilton's interview, Camille is looking at an active computer screen despite it being unplugged.
Episode #1.7 - S1-E7
Revealing mistake: When the guitarist punches the bass player in the face you can see him miss. (00:50:02)
Episode #2.1 - S2-E1
Revealing mistake: Richard at home is reading a book on slavery. An English book, at least the cover and the big header of the first internal page are in English, and about slavery. But a quick peek before the cut easily reveals that the book is written in French and talks about cocktails. (00:28:10)
Episode #2.5 - S2-E5
Revealing mistake: When Ben Miller asks for the forensics report on the oyster and shot glass, the report has egregious spelling mistakes ("Specimin" instead of Specimen) and shows the victim testing positive for Oxycodone rather than strychnine! For the record, it is an entirely different lab test (a real one, with 'specimen' spelt correctly) done for a patient under prescription medications (morphine, oxycodone and benadryl) and its date is inconsistent with every other episode (it's a 03/19/2010 document and in the first season it was established the year was 2011), but these last details can be noticed only if you freeze-frame. (00:42:00)
Episode #2.7 - S2-E7
Revealing mistake: When we see the killer deal the fatal strike, the pipe misses a mile to the left. (00:48:00)
Episode #3.1 - S3-E1
Revealing mistake: When Goodman looks at the two old pictures from the graduation ceremony side by side, they are blatantly photoshopped in a poor way; look at the way the characters stand out from the background, the light on the man on the right of the left pic, and there's even a frock or bag that two of the women carry that is a copy/paste from one picture to the other. (00:39:10)
Episode #3.7 - S3-E7
Revealing mistake: Dwayne aided by Emily is bringing in the two boxes of papers from the storage. Transporting them is a difficult task with the storm that is raging on. A strange storm that happens to shake the plants in the foreground, but with Caroline Proust's hair and the leaves of the trees on the other side completely untouched. (00:16:40)
Episode #3.7 - S3-E7
Revealing mistake: Goodman and Bordey are interviewing Terrance Jackson after the revelation involving Rosie. During the scene, in most shots despite the storm that supposedly is happening, the leaves outside are subjected to a gentle breeze if at all. (00:26:00)
Episode #3.7 - S3-E7
Revealing mistake: Dwayne finds a newspaper which hilariously happens to have a perfect close-up photo of one of the suspects out of the thousands of protesters, right on the first page. Couple of problems with it; first, the text is just 2 paragraphs copy/pasted all over, and second, more blatant; the caption of the photo says "Valerie Clayton", but Dwayne just called her "Valerie Pellow." (00:33:00)
Episode #4.2 - S4-E2
Revealing mistake: Camille puts the name of the victim and "Watergate" as search terms, and manages to find the relevant news item from the past. The URL of the website though is just the one of the (fictitious) homepage (watergatenews.org), and not of a specific article. Moreover, the article is half relevant info, and half generic guide about surfing with a brisk cut from one to the other. (00:21:50)
Episode #4.5 - S4-E5
Revealing mistake: Florence prints the first page from the Saint Marie newspaper, from a generic "Thursday 12th"; the whole first page is taken by the news of the fire destroying the recording studio...but half of the article talks about "the world's largest message in a bottle", instead. (00:16:25)
Episode #4.6 - S4-E6
Revealing mistake: Florence passes a mug of coffee to her boss, who goes on to sit in his chair and have a tragic overacting accident. However, when things were still normal and he merely approached the desk, you could see Florence already stop drinking and frown preoccupied before anything bad happened. (00:06:10)
Revealing mistake: When Humphrey checks out of the mail from the dating website at the end of the episode, behind the window of the mail client, there's a fingerprint file with the name "Adam Frost" and a 2014 sampling date; it's a file recycled from two seasons before, 3-4. (00:49:55)
Revealing mistake: While they are checking out Matt Holt's discount Facebook page (Face-spaces dot com) on the computer, behind the browser window there's an open file with a fingerprint, and like in another episode of this series, it's a fingerprint not related at all to this case, but one from three years earlier, the episode of season 3 "Ye of Little Faith", this time from the victim of that case Natasha Thiebert. (00:26:30)
Revealing mistake: Florence and Humphrey are reading the article about the young Dexter Allen from the Hackney Gazette. Behind the article, Florence has her mail open. Amazingly enough, the names of the people she received mail from (Joshua, David, Faye, a Customer service) are the same ones as the victims in She Was Murdered Twice, season 4 episode 7 when one of the suspects opened it from a public computer. (00:30:45)
Revealing mistake: Dwayne supposedly swapped the rum with Humphrey, but if you pay attention during the time when JP hands them the glasses, it simply does not happen. (00:26:00)
Revealing mistake: When Dwayne holds the copy of the local newspaper with his goat comment making the headline, the text of the article repeats itself; you can see aligned in both columns the name of the commissioner accompanied by "pictured right." (00:23:15)
The Secret of the Flame Tree - S6-E2
Revealing mistake: The sepia-toned memento that Florence spies on the wall of Chez Lulu is supposedly from 1969, certainly a photoshop horror from 2017, with the faces of the two siblings ghastly superimposed. (00:24:25)
The Secret of the Flame Tree - S6-E2
Revealing mistake: Florence shows to her boss a copy of the birth certificate of Lizzie Baptiste. It is signed "Overseas British Territory of Saint Marie", dates back to 1954 with a photostatic copy of the original typewritten entry, and her school certificate is also written in English. Saint Marie though, according to its fictional history, was part of France at the time, having been a British territory only for 30 years before Season 1 (set in 2011). (00:25:40)
The Secret of the Flame Tree - S6-E2
Revealing mistake: At Catherine's, Dwayne is reading a copy of The Saint Marie Times, announcing the new candidate for Mayor. The text used in the prop though, is obviously the same used in the prop for the first episode of the season - the article is all about Commissioner Patterson. (00:26:20)
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.