Continuity mistake: When Dany dies, the blood trails coming from her mouth and nose are pale in some shots and dark in others. They also appear to change position slightly, but that might just be the camera angle.
Continuity mistake: At this point, Jamie Lannister has lost a hand at the, well, hands of his captors. As they shove him to his knees in front of Lord Bolton, he uses both of his hands, with no stump being visible. (00:12:39)
Continuity mistake: When King Robert arrives at Winterfell, the wide leather straps of his cloak are crisscrossed with his left over his right, but when Robert and Ned walk inside the crypts, Robert's straps are crisscrossed the opposite way, with his right over his left. The shots are not flipped.
Continuity mistake: When Bran is taken from his horse in the woods, there are 3 wildlings that attack. The first Rob cuts his throat, the second, Rob is holding the female wildling by the hair, he then spears and kills the third with his sword and the very next frame the 3rd wildling is then holding a knife to Bran's throat, unharmed. (00:11:15)
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)
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 Tyrion is talking to Sandor, his position in relation to the gate changes between camera cuts. In the first shot he is next to the gate. In the second shot he is about 3ft away. (00:06:20)
Continuity mistake: When Sam hands the bureaucrat the letter from Jon Snow, in the shots facing the bureaucrat, the wax seal is on the left side of the envelope (when seen from Sam's perspective). In the shots facing Sam, the seal is on the right side of the envelope.
Continuity mistake: When Ser Jorah tells Dany that her life with Khal Drogo "will get easier," watch the strap of her dress. It moves up and down her right shoulder throughout the scene. (00:03:05)
Continuity mistake: When the Faith Militant descend on Ser Loras Tyrell's training session there is a shot after the Militants have come down the stair of Loras fighting from behind a man's shoulder, in this shot you can see they are fighting on grass surrounded by walls with sheer drops with no entry point other than the stairs the militants walk down. In the next shot you can see the 9 militants that have come down the stairs approach Loras from one side, but suddenly 6 militants join him from the opposite side, where they definitely were not before. In the zoomed out shot you can see there is nowhere for these men to have come from. (00:11:15 - 00:11:50)
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.
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.
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)
Cripples, Bastards, and Broken Things - S1-E4
Continuity mistake: When Ned and Petyr are walking and talking about Sir Hugh of the Vale, they are in brilliant sunshine in one shot then in an instant cut there is no sun. (00:28:05)
Continuity mistake: At Daenerys' wedding we see a man get sliced across his midriff and lean backwards with his mouth open. Camera does an instant cut and now he is slouched forwards. (00:52:00)
Continuity mistake: In the scene in the amphitheatre, while seated in the royal box, Daenerys is wearing a full length white gown with flat pumps and an ornate silver necklace with a large dragon motif on the left side. During the revolt when she is seen running across the fighting pit the dress is shorter and she seems to be wearing some sort of leggings underneath it. Daenerys escapes on the back of her dragon and when we next see her in episode 10 she is wearing a completely different knee length pale blue gown. The necklace also seems different with her hair spread out on her left shoulder to disguise the lack of the dragon motif. She is also wearing grey boots with a fairly high heel. Obviously dragons come with a secret baggage compartment.
Continuity mistake: Towards the end there is a body of a dead Son of the Harpy lying between the fallen Unsullied and the side corridor visible in the wall, located very close to either. In the next show the body is gone. Also, as the camera angle changes, the blood stains on the walls look differently. (00:48:50)
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)
Chosen answer: Well Magic does come to mind. The White Walkers bring with them the winter. Because of this, the seasons are very unpredictable. "Winter Is Coming" refers to this.
lionhead