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.
Plot hole: Because Katara lost her mothers necklace, Aang made one for her and she puts it on. But when they reach The Fortunetellers village, Katara is not wearing the necklace, and no one notices, not even Aang.
The Boy in the Iceberg - S1-E1
Continuity mistake: In this episode, Katara remarks that "This ship has haunted my tribe since Gran Gran was a little girl. " However, in the episode "The Puppetmaster" it is revealed the ship wasn't beached there until Gran Gran was in her late teens or early twenties.
Suggested correction: You sure that was the same ship, and what's 5-10 years give or take compared to Gran-Gran's life anyway?
Suggested correction: If Gran Gran was really in her late teens or early twenties during the Southern Water Tribe raids, that can still be considered a "little girl," since she is in her eighties in the show.
Imprisoned - S1-E6
Continuity mistake: When the gang meets Haru, Katara teleports from behind a log (shoulder still visible) in one shot to greeting Haru several yards in front of the log a split second later. (00:02:50)
Suggested correction: That's because the second shot is a jump cut. The trio first sees Haru from behind the log, and after Sokka says, "He looks dangerous, so we better approach cautiously," the scene jumps forward in time to Katara greeting Haru further away from the log. Katara simply got closer to Haru, which was not shown.
The Ember Island Players - S3-E17
Other mistake: When they are watching the recap play Toph says she can't see it because they are on a balcony, but when her character comes on she describes him as buff.
Suggested correction: She didn't see him (or technically, feel him), but she heard him. The actor playing her character throws the huge prop rock, and it hits the stage floor. Then, he flexes his muscles. Toph heard all this happening from her seat and then said, "I sound like a guy. A really buff guy."
