Character mistake: After Nick kills Calvin, and Travis arrives, Nick calls Travis "Nick" before correctly calling him Travis in his next line of dialogue.
Suggested correction: Travis is the one who says "Nick".
Looking for Mr. Goodbrain, Part 2 - S3-E13
Character mistake: When Liv and Clive are talking to Chase about Katty, Liv tells Chase he had a cocktail napkin with Katty's phone number on it. However, it was only Katty's hotel room number that was on the napkin, which Liv saw.
Character mistake: The way Henry takes Barry's blood pressure, he will not get any results. Neither the blood pressure cuff nor the stethoscope work reliably through clothing. As a doctor, he should know how to do it right.
Character mistake: S44/E80 Noah Newman works as a bartender, and while at Victor Newman's house says "let's show off some of those drink serving skills." While making a drink he pours straight vodka from the bottle into a martini glass and puts in olives and hands it to Abby to drink. As bartender Noah should know how to make a martini. He doesn't use any vermouth with the vodka and doesn't chill it first by shaking or stirring it before pouring it into the martini glass. (00:11:00)
Character mistake: Rufus says "That was before I found out you raped my 14 year old daughter." referring to Jenny. Jenny, in previous seasons is 15. Jenny was born in 1993, and season 4 was filmed in 2010, making Jenny 16 at least. (00:25:35)
Character mistake: In an early episode, Villa mentions Rosewood's "banana colored" '69 GTO to his then girlfriend. Rosewood's GTO is a "banana colored" '68 GTO.
Character mistake: At Houdini's performance for the Kaiser, a German officer with the rank of Lieutenant Colonel (Oberstleutnant) is asked to assist. Houdini at first correctly addresses him as Lieutenant Colonel, but then incorrectly refers to him as Lieutenant several times after that.
The Singer - S7-E5
Character mistake: Near the end, Matlock says that he can prove who killed KC. The burden of proof lies with the prosecution; as a defense attorney, Matlock doesn't have to prove anything.
Character mistake: The date on Louise's plane ticket to London is listed as "Thursday 16 February 2017", but the month "February" is missing the U, misspelling it as "Febrary." (00:15:56)
Character mistake: Upon finding the Spanish flu virus missing, Hardison freaks out about it killing 50m people 100 years ago, saying it would be even more deadly today due to the higher population. There's no reason to think so - the death toll in 1918 was massively exacerbated by the aftermath of WWI. Not to mention today we have vaccines, plus most deaths then were actually caused by bacterial pneumonia, which today is easily treated with antibiotics.
Episode #4.1 - S4-E1
Character mistake: Ruth requests a search of London streets with the name "Achilles" in them. A list of streets appears on a computer screen, but when one of them is selected, it is spelled "Achillies."
Character mistake: Bobby gets injured in a racing accident. When the family is told by Greg that Bobby is paralyzed and can't walk, Marcia starts to smile, then quickly changes to a sad face to match the situation.
Compromised - S1-E9
Character mistake: When she and OA meet Marshal Ackerman, Maggie is somewhat surprised to learn Damon Cruz was a federal witness. As a federal agent herself, Maggie surely would know that the Marshals Service's mandate includes the witness protection program.
Character mistake: Nick asks Janette if she's ever turned anyone else into a vampire - an odd question, considering the fact that he already knows she has. He was there when she brought the baroness across in the 18th Century flashback sequence for "If Looks Could Kill." It's even odder that Janette tells him she's never done it, since she knows that Nick knows she has. Apparently, the only one not in the know here was the scriptwriter.
Character mistake: The X-ray shown when Ruth see Cade's body is placed in the wrong way. It should have been a mirror image. (00:57:56 - 00:59:06)
Character mistake: The note Six hands the "access man" misspells the word "receipt" as "reciept." He's supposedly a "think tank" genius, so really should be able to spell better than that. (00:27:30)
Episode #6.4 - S6-E4
Character mistake: The character pretending to be Lt. Ellis refers to himself as First Lieutenant. That rank is referred to orally as "Lieutenant", not "First Lieutenant."
Angel of Mercy: Part Two - S1-E4
Character mistake: When Lenore Osgood is speaking on the phone with Charles Wainwright about killing Dr. Hanover, she mispronounces "Larynx" as "Lar-nix."
Children of Earth: Day One - S3-E1
Character mistake: Lois says that Colonel Aduya's uniform "isn't British Army". In fact, it is entirely (and accurately) British Army with the exception of the small UNIT badge over the pocket.
Lovelines (aka The Eddie) - S6-E19
Character mistake: In the scene when Dr. Drew has Joey and Eddie on stage, they are arguing and Joey says that Eddie moved away and dumped her twice. Actually, he only dumped her once, when he moved out of his apartment and back home with his parents. The 2nd time that Joey is referring to is when Eddie moved to California for the writing workshop, which SHE helped and encouraged him to do. So he did not dump her 2 times; she basically pushed for him to leave the 2nd time, yet she acts as though this situation never occurred.