Continuity mistake: When Buckingham is about to be arrested, the camera is looking directly at him. At this angle, his black fur collar is flipped up, covering the neck of his white shirt. When the scene changes to a wide shot behind him, the collar is folded down.
Revealing mistake: In episode 2 during the scene when the king's son is born, it appears that the baby has been born for less than a few minutes, but when he is held up it is plain to see that his navel has healed instead of being freshly cut as it should be after the birth.
Deliberate mistake: Around the 26 minute mark, when Charles Brandon joins Margaret for a game of cards during their voyage to Portugal, Margaret has a glass of wine (and later Brandon) in which the liquid is not sloshing around as it should be on a ship that is rocking and swaying the way it should.
Revealing mistake: In the scene where the King's sister is throwing things at Charles in rage, she says "don't call me wife" and hurls a goblet at him and it hits the window behind him. A sound of breaking glass is heard, yet you can see the plastic 'window' flap and the 'glass' stays in tact.