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.
Plot hole: Jon sends a raven to Daenerys in Dragonstone, and Gendry runs back to Eastwatch, reporting their dire position. Both of them get there surprisingly quickly, and then Daenerys manages to fly to them in basically no time at all, despite them being at least 1,500 miles apart, according to previous distance implications.
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.
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.