When Tyrion hands Missandei a drink, the level of wine in the glass changes between shots.
Brienne tells the Blackfish "Ser Jaime kept his word to your niece Catelyn Stark. He sent me to find Sansa, to help her as Catelyn wanted." Actually, Jaime did not keep his word; he swore that he would return the Stark girls to their mother (The Bear and the Maiden Fair (2013)), not just help Brienne find them, and not only in respect of Sansa. Jaime had a chance to try to help Sansa escape in Two Swords (2014), but he blew it; when Brienne reminded him his promise - he refused.
Fleeing from the Waif, Arya is shown falling down the steps, crashing into the cart of a fruit peddler. After rolling down in a cascade of oranges, she comes to a standstill on a landing. Then, a second or so back in time, purely for the sake of seeing the stunt from a different camera angle, she is seen rolling down the steps again, coming to the same inert position. It is not in keeping with the long-running show to have an instant replay of a dramatic event, just as in real life there is no instant replay of anything happening.
After the hanging of the Brotherhood outlaws, when the Hound kneels to take the man's boots, the noose around the third man's neck is visibly loose and flops around as he dangles.