Tywin tells Joffrey that the dragon skulls that once lined the throne room were arranged largest to smallest, with the smallest next to the Iron Throne. In Cripples, Bastards, and Broken Things (2011), Viserys tells Doreah the opposite, that the largest skull was next to the throne.
The pieces of the broken wooden sword are gone in the final overview.
After the bear is shot, the man who shot him has a still cranked crossbow. When the camera angle is changed, the crossbow is not cranked.
When Razdal offers gifts to Daenerys, his servants bring two chests with gold, two men carrying each. Gold is one of the densest materials, thus each of the ingots shown would weigh around 20 kg (44 lbs). The total weight of each chest would require a forklift truck.
When Jaime is lifted out of the bear pit, his bandaged right hand is visible; when Brienne grasps his left hand, he grabs the wooden beam with a un-amputated and un-bandaged right hand.
When Jon and Ygritte are heading south after crossing the wall with the wildlings, they stop for a rest, and Ygritte removes something from her shoe. When she does this, she turns the shoe over to shake it out and the visible sole of the shoe is a standard, modern hiking boot sole.
As Razdal and his slaves walk towards Daenarys' tent, a slave in the front plays a marching drum. During the last few steps to the tent, the drummer's strikes very clearly do not match the sound of the drumming.
After Ygritte and the wildings have crossed the wall, the land is green and the climate noticeably warmer, yet they continue to wear the furs that were keeping them warm in the icy climate. They would be overheating.