Character mistake: When Jet tells Katara and Aang to waterbend the water from underground in the geysers, Katara states that she has never waterbent on water she couldn't see before. However, six episodes prior to this, in 'The Warriors of Kyoshi', she waterbends the water out from Aang's lungs to save his life.
Suggested correction: That was a moment of desperation on her part, and she probably doesn't think of it/think she can do it again without the same desperate impetus, Furthermore, the water in Aang was only a small amount and very close anyway.
Regardless of if she did it in desperation or not, she did use bending on water she didn't see. The mistake isn't suggesting anything about Katara's ability to waterbend unseen water, the mistake is only in regards to the statement Katara made about never using bending on water she can't see. And for Katara to forget the one time she used bending on water she didn't see would qualify as a character mistake as well. Now if she made the statement "I don't think I can do this" or "I've never used bending on underground water", etc, that would not be a character mistake.
Character mistake: Elliot Stabler is interrogating a suspect and he says "Well maybe he got pissy because of the 2.2 you blew into the breathalyzer." He said two-point-two but he meant point-two-two because a 2.2 BAC is like 5 times the lethal limit, so a 0 .22 BAC makes more sense. (00:20:10)
Catch A Falling Star - May 21, 1979 - S2-E10
Character mistake: In the preview for this episode, Charlie has trouble getting his countdown straight. He shouts that Sam is on in 50 seconds, then 47, then 48. In the episode itself, the mistake is corrected with a rather obvious overdub, changing the final number to 43. (00:02:05)
Character mistake: Ben Stein asks a chemistry question about -273° Kelvin. The problem is, the scientific community never uses the word 'degrees' when referring to Kelvin. The correct way to say it would have been, "-273 Kelvin is also known as what?" Also Kelvin cannot be negative since 0 kelvin (approx -273° Celsius) is absolute zero.
Character mistake: Captain Crane has Bentley collared and is questioning him. An alive Lee Crane asks Bentley "why did you kill me?" He quickly changes it to "why did you try to kill me?" (00:10:40)
That Little Old Matchmaker, Martin - S1-E12
Character mistake: In Bill's office, after Tim talks about the acoustics in the building, Bill calls Tim "Bill." (00:15:51)
Character mistake: At the Roadhouse Cooper states that the second victim (Maddy) was found dead two days ago. It has been less than 24 hours since the body was found: he likely means she was murdered two days ago.
Night of the Living Dummy III (1) - S2-E24
Character mistake: When Zane sees Rocky with the hockey mask, he seems legitimately terrified when he notices him. However, he was responsible for putting him there and no-one else was around. There is no reason for him to express real fear when he planned for his appearance the whole time. (00:11:44 - 00:12:08)
Suggested correction: He only pretended to be scared in order to fool his cousins, uncle and aunt.
Character mistake: During the radio show, the radio host gives the radio station's phone number as 555-4455, Alf then softly repeats the number back before he gets to the phone. He then picks up the headset and dials a number, but the numbers he presses on the phone don't match up to the number given by the radio station. (00:04:10)
Character mistake: During the television report about the Sun Probe, a diagram shows the solarnauts' control cabin within the Probe Module. But we later see that the control cabin is within the body of the Probe Rocket when the Module is fired into the solar prominence.
The Alexander the Greater Affair (1) - S2-E1
Character mistake: When Alexander organizes the human chess game in his courtyard, the "pieces" stand the wrong way on the board, with a dark square in the lower right hand corner. That corner is always a light square. (00:22:50)
Character mistake: At the end of April and the beginning of May in 2004, Luis was decoding the CDs with the Crane secrets on them. For an extended period of time, Luis left the CDs completely unattended at Hank's house. Luis told several different people that the computer was decoding the CDs and didn't need anybody there to do it. Given that Alistair is virtually omniscient in Harmony, it's ridiculous that he didn't break into Hank's apartment and take the CDs.
Firestarter - S3-E2
Character mistake: In the beginning of the episode, the new social worker says "it's been raining all night, what do you expect?" whereas later in the 'flashbacks' he says, "what do you expect, it's been raining all night".
Character mistake: Scully continually addresses the senior police officer as "Captain." But he wears sergeant's stripes. As a law enforcement officer continually dealing with other law enforcement officers, Scully is not likely to make this mistake. More likely a failure to match script with costume.
Character mistake: Will's tax demonstration to his volunteer staffers is incorrect. He applies the various tax rates to the entirety of each salary range. The person who makes $150K and is in the 36% rate...in his example he has them paying 36% on their entire salary, not just the portion of it that puts them ahead of the next lower tax rate. If the tax rate jumped to 70% at income of $1M, and a person earned $1,050,000, they wouldn't be paying the 70% rate on all $1,050,000 of their income, only the last $50,000 of it. Will's example makes it look like they would be.
The Battle of Central Park - S3-E6
Character mistake: When Justine Feraldo looks at the checkpoint feeds, she says that the Strigoi have overrun the checkpoint at 116th Street and 110th and Amsterdam. But the feed says 118th and Amsterdam.
Character mistake: When Mikey looks at the Picture Day schedule, he points out that 4th grade is going last. However, the schedule says they are after 3rd grade and before 5th grade, actually making them fifth. The faculty is actually listed last on the schedule.
Character mistake: When Rose thinks Mickey is dead, she says she'll have to tell his mother. But in Rise of the Cybermen in Series 2, she says that Mickey's mother has been dead since he was a child. (00:30:17)
The Peruvian Puff Pepper - S3-E2
Character mistake: Drake says he hasn't been in Megan's room since he was five, but he brings Grammy's bags up there in the episode "Grammy".
On the Run - S3-E13
Character mistake: When Mrs Haldane is giving her statement to Regan she tells him that Cook was wearing dark glasses when she saw him outside her neighbour's house, but Cook wasn't wearing any glasses.