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)
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 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.
Continuity mistake: When the camera pans out from Jon and Ygritte standing on the wall kissing, Tormund and Orell, who were sitting next to them, are nowhere to be seen.
The Bear and the Maiden Fair - S3-E7
Continuity mistake: Jamie is getting his stump tended to and some white ointment is rubbed onto it before it is rebandaged. Before the bandage is placed however, the ointment disappears.
The Rains of Castamere - S3-E9
Continuity mistake: At the climax of the Red Wedding massacre, Robb crawls towards his dead wife Talisa from the direction of the doors, which are at the opposite side from Walder Frey's throne. Robb turns Talisa onto her back from her left side (ie. he is on the right hand side of her body), and looks down at her face. This means that Talisa is lying in such a way that, if facing Walder's throne, her head is on the right and her feet on the left, towards where Catelyn is holding Walder's wife hostage and pleading for Robb's life. However, when Walder refuses, Robb has changed position and is now on the left side of Talisa's body, which is presumed to be facing the same direction as before as there is no reason for it to have changed. Robb then turns towards Catelyn who is still on the left side of the room (if facing from The Door), and is stabbed by Roose Bolton. As Robb collapses to his death, looking directly at Catelyn, he lands next to Talisa, whose head is now closest to Catelyn with her feet facing the other way, meaning that her body has somehow rotated by 180° in a matter of seconds. This is an especially bad mistake considering that several people have claimed the Red Wedding was completed in one take, which is not possible if this error exists unless Oona Chaplin for some reason decided out of boredom to play spin the bottle with her own body while out of shot, which would have interfered with Richard Madden's position anyway. (00:47:00 - 00:50:00)
Two Swords - S4-E1
Continuity mistake: When Arya and Hound come upon the murdered people Arya is riding facing left. After they pass, she is facing right. (00:48:40)
The Mountain and the Viper - S4-E8
Continuity mistake: When Oberyn first tells Gregor that he will make him confess to raping and killing his sister Elia and her children, he is holding his spear with both hands. In the next shot, he's holding it with just one hand.
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 ★