The Hairy Scare of the Devil Bear - S1-E8
Character mistake: Velma says bears only have four claws. Wrong, they really do have five claws.
Character mistake: Mahershala said the child found in the cement had "osteoportrosis", instead of osteoporosis. Then the grief counselor repeated the same incorrect word.
Suggested correction: They said "osteopetrosis," which is a different medical condition from osteoporosis. Osteopetrosis is a genetic condition that causes overly dense, brittle, and misshapen bones starting in infancy.
Character mistake: Logan tells Heather that Mario Kart (Double Dash) has an online mode. It does not.
Character mistake: In the epilogue, Charlie illustrates the relationship of mathematics to real life by discussing the golden ratio and its presence in a host of real-life situations, including the shape of a nautilus shell and the distribution of petals in a flower. These claims are disputed by some mathematicians (see http://en.wikipedia.org/wiki/Golden_ratio#Nature), and the one about the nautilus shell one is untrue (see http://en.wikipedia.org/wiki/Golden_spiral#Spirals_in_nature). It's possible Charlie is just repeating what he has read or heard without investigating it for himself, but this is uncharacteristic of him.
Character mistake: Sasha refers to the 'murder' on Thursday 4th June 1982. The date in question was on a Friday.
Character mistake: When Rich refers to the film showing Davis (decades ago), he figures they were in "Asia... Mongolia or somewhere." However, the film cannister had "Tibet, 1937" written on it - important enough to show the audience, but not for the character to read? (00:40:25)
Character mistake: When Collier is meeting all the 4400s at the reunion, Shawn calls Isabelle Maia by mistake. (00:31:10)
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.
First Blood - S12-E9
Character mistake: Sam points out Elk Mountain, but there is no Elk Mountain in Rocky Mountain National Park.
Character mistake: Dr. Sloan and Quinn are in the victim's apartment. Right before Dr. Sloan opens the door for the old lady witness to ID Quinn, Dr. Sloan says, "saw a man visiting Holly the night before he died." Holly is a woman. Dr. Sloan should have said "she." (00:33:51)
The Tale of the Manaha - S5-E7
Character mistake: Near the beginning as the leader is about to set off with the boys, he says, "About face!" and turns to the left, and the boys follow suit. But "About face" means to turn 180°. He should have said "Left face" to get them to turn 90° to the left. (00:04:25)
God Is in the Details - S2-E10
Character mistake: When Diane quotes the scripture, she says "Revelations." However, it's just "Revelation." Someone as smart as her who has read the New Testament (or heard it quoted) would know the correct word.
Character mistake: Maxwell translates his famous line "And loving it' into the German 'Und damit gefreut'. Agent 99 who claims to speak German fluently confirms it. This translation is both far away from the meaning and doesn't make any sense at all. The right translation is 'Und liebe es'. (00:09:50)
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.
Flashpoint - S1-E5
Character mistake: Chief Pope threatens to take away Lt Flynn's stripes. Lieutenants don't have stripes.
Character mistake: The doorman tells Ike that Jimmy Shoes and the prostitute left in a '55 Chevy, the car is a '56 Chevy.
Character mistake: Nathan suggests to Dwight and Audrey that maybe he should shut down the meeting of troubled people. As chief, he should know he has no authority to stop citizens from assembling.
The Dark and Bloody Ground - S1-E3
Character mistake: Clyde Russell tells Rockford to meet him at his place in "Ambazac Road in Bel Air." The name of the street in real life is Ambazac Way. (00:38:20)
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.
The Case of the Wandering Widow - S4-E6
Character mistake: As Mr. Morgan (Dean Harens) is being examined by the prosecutor he's also sitting in the gallery.