Continuity mistake: When Ser Vardis has cornered Bron right at the edge of the moon door the position of Bron's body changes between shots. When the shot is taken from inside the moondoor, Bron's body leans backwards, over the moondoor. But when the shot is taken from behind the throne Bron is leaning forward.
Continuity mistake: When Jorah gets his royal pardon, the wax seal is hanging freely. Camera changes and now the wax seal is resting on his fingers. (00:31:00)
Continuity mistake: When Jon and the others emerge onto the other side of the wall, there are 4 people with torches. Pay attention to the one at the back on the screen left. He has his torch in his left hand in this shot, but as the shot changes to the front he now has his torch in his right hand. (00:44:30)
Continuity mistake: When the group of men emerge at the other side of the wall, the last man with a torch has it held vertically. Camera cuts and now it is held at around a 45 degree angle. (00:44:30)
Continuity mistake: When Jon is taking his vow at the tree, the red markings on the tree change between shots. 2 single lines become joined, and a third single line becomes less smudged. (00:45:00)
Continuity mistake: Arya and Syrio are practising at the start, we see them stop with their swords touching and crossed. Camera changes and Syrio's sword is much lower and no longer touching Arya's. (00:02:10)
Continuity mistake: Catelyn confronts her sister about the raven's message that arrived at dawn. When she does, the roll of paper is rolled completely differently between the 2 camera angles. (00:16:05)
Revealing mistake: Just after Jon is told he is confined to quarters, there is a shot of outside with snow falling. However the snow is actually rising. Indicating the shot has been reversed. (00:22:55)
Continuity mistake: When Catelyn meets up with Robb's forces, she hugs her son and then puts her hand on his shoulder/chest. In the next shot, her hand is down by her side. (00:41:40)
Continuity mistake: When Ser Barriston throws his armour and sword on the floor after being demoted, the armor and sword are inside the black tiled square on the floor. Camera changes to show Sansa kneeling before the council and now the armor and sword are outside of the black tiled box despite no-one touching it. (00:52:30)
Continuity mistake: When Ser Barriston throws his armor and sword on the floor after being demoted, the sword stops by his armor. However when Sansa kneels down, the sword is now a good distance from the armor. (00:52:40)
Continuity mistake: When Tyrion is explaining where he has been and what he has been doing, he grabs a jug of wine by the neck. When the camera changes he now has it by the body of the jug. (00:07:30)
The Ghost of Harrenhal - S2-E5
Continuity mistake: Brienne and Lady Catelyn are with their horses by a stream talking. Brienne's white horse is walked into picture and is very dirty. The next shot the horse is clean. (00:38:40)
The Ghost of Harrenhal - S2-E5
Character mistake: When Renly and Catelyn are negotiating the terms of Renly's alliance with Robb, Renly calls Moat Cailin "Moat Caitlin." As someone who served as Master of Laws on King Robert's Small Council, he should know the correct name of the territory he is referring to.
The Old Gods and the New - S2-E6
Continuity mistake: When Maester Luwin walks towards Theon to try and talk him out of executing Ser Rodrik, he places his right hand on Theon's left shoulder. When the shot changes, his hand is no longer on Theon's shoulder.
The Prince of Winterfell - S2-E8
Continuity mistake: In the scene where Tyrion and Cersei are talking about sending Joffrey to the battlefield, Tyrion removes his cloth napkin from his shirt twice. (01:18:50)
Dark Wings, Dark Words - S3-E2
Continuity mistake: When Brienne of Tarth is facing off against Jaime Lannister on the bridge, in a shot from behind the blade is angled upwards, not touching her arm, then in the immediate next shot from the front the blade is now lying along her arm.
Revealing mistake: At the beginning of the episode, Robb and Blackfish Tully are pushing Hoster Tully's funeral boat down the river. When they climb back onto the dock, there is already a trail of water going from the steps and ending where Robb ends up standing. None of the other characters standing on this portion of the dock have wet clothes, meaning none of them went into the river, indicating that the trail of water was from previous takes.
Answer: Basically it's because he broke his vow. A member of the Kingsguard is sworn to protect the king at all costs. Jaime elaborates more on the deed to both Catelyn Stark and Brienne of Tarth, telling Catelyn that no matter what course of action he took, he would be breaking one vow or another (i.e. if he obeyed the king, he would conversely be disobeying his own father), and telling Brienne that the Mad King was planning on burning all of King's Landing, but he did not bother to tell Ned Stark that. Ned Stark felt that killing Aerys was dishonorable and excessive. Robert Baratheon still could have usurped the throne without Aerys being killed.
Phaneron ★