The Tales of Ba Sing Se - S2-E15
Other mistake: The Tale of Aang: After Aang lets all the animals out of the zoo, he takes out his bison whistle and blows on it. As he does so, the way he holds his staff makes it so that it's going right through his head. (00:10:28)
Continuity mistake: After Sokka admits to Piandao that he thought he messed up everything they worked on, when Piandao says, "You messed things up in a very special way," the yellow trim at the front of Piandao's collar is incomplete. The yellow trim is rendered properly when Piandao says, "Your sword must be an extension of yourself." (00:13:55)
Other mistake: When the group is first shown inside the store, Sokka starts running forward. Toph stands behind Sokka, but as Sokka is running away from them, she is layered over him. (00:04:43)
Continuity mistake: When Piandao tells Sokka that creativity, versatility, and intelligence define a great swordsman, he holds out Sokka's sheathed sword with its hilt at Piandao's right hand. However, in the next shot facing Sokka, the sword in its scabbard now lies on Piandao's hands the opposite way, with its hilt at Piandao's left hand. The position of Piandao's hands and thumbs changes as well, between shots. (00:17:25)
Continuity mistake: Toph mentions the worst thing about being disguised is they don't get the hero worship anymore and she misses the love, to which Sokka grumbles, "Boo-hoo, poor heroes." Then, as Sokka says, "It's just, all you guys can do this awesome bending stuff," the triangular emblem on Aang's red "headband" has vanished, and in the next shot, it reappears. (00:03:35)
Other mistake: When Aang is reading the letter from The Guru, as Sokka says, "What's a guru? Some kind of poisonous blowfish?" his right eye loses its white colour three times during the shot. (00:18:19)
Continuity mistake: When Ghashiun orders the sandbenders to ransack Appa's saddle, Appa's eyes are closed. In the next shot, they are open, then go back to closed in the following shot. (00:02:23)
Continuity mistake: After Meng gives Aang the tray of food and Sokka takes it from him, Aunt Wu shows up, and it shows a shot facing her front. In this shot, Katara's back braid is missing; then it reappears a moment later. (00:07:05)
Sozin's Comet (1): The Phoenix King - S3-E18
Continuity mistake: When Aang is waking up on the giant lion turtle, he is not wearing shoes in the first shot, but in the next shot, he is. (00:22:35)
The Southern Air Temple - S1-E3
Other mistake: When the gang is in the Hall of Statues of Past Avatars, Katara points out the avatar cycle pattern of statues and Aang zeroes in on Roku's statue. The earthbender avatar statue next to Roku is of an unknown man with a sword, not Kiyoshi. (00:12:50 - 00:13:35)
Avatar Day - S2-E5
Continuity mistake: When the village leader switches the wheel of punishment to Community Service, it is on the space next to Boiled in Oil. However, all of the other shots of the wheel have another section in between these two.
Bitter Work - S2-E9
Continuity mistake: When Iroh draws the symbols of the Four Nations in the sand, there is grass on the left side of the Earth symbol in the close ups. In the shots that show all four symbols, the grass is gone. (00:14:25)
Other mistake: When Azula attacks The Western Air Temple, there is a close up shot of her when she says that she is about to become an only child. Pay attention to the smoke coming from the airship behind her, especially above her head: it doesn't move. Even if this was remotely possible, it does move when the camera zooms out, making it a mistake nonetheless.
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.
Bato of the Water Tribe - S1-E15
Other mistake: When Katara is behind Sokka and he is speaking she leans back and as she does her eyes stay in the same place while her head moves, then it fixes itself. (00:16:20)
Continuity mistake: When Katara is trying to heal the wounded earthbender, she gives Sokka the idea to take down The Drill from the inside. Sokka then stops her from saying anything while she is sitting down, and she is wearing her necklace. When she stands up in that same shot, the necklace is gone, like they forgot to animate it. (00:07:35)
The Southern Air Temple - S1-E3
Continuity mistake: When Gyatso is laughing in Aang's flashback, he is missing quite a few teeth. But when Aang finds his skeleton, all his teeth are still in place.
Avatar Day - S2-E5
Continuity mistake: When we first see Aang in the stocks, Sokka advises him to use his Airbending to escape and begins "imitating" Aang's kata. During one pose, we see Sokka is wearing the boomerang, or at least the sheath it was in, that he had to leave behind at the beginning of the episode. He wasn't wearing it before, isn't wearing it after, and doesn't actually get it back until the climax. (00:02:09 - 00:06:33)
Continuity mistake: When Aang emerges from the water on the giant sprout in The Avatar State, the arrow on his head is not glowing.
Audio problem: At the end of this episode, Aang tells Katara that forgiveness is the first step you need to begin healing. But if you watch closely, his mouth isn't moving at all when he says this.
