After Henry's jousting accident, dried blood can be seen on his face that runs from his temple down his cheek. That pattern only makes sense if he were sitting upright; however, he is flat on his back and unconscious, so the blood should have run from his temple towards the back of his head.
During a feast scene, a musician is playing Henry Playford's "Mr Beveridge's Maggot" which was not composed and published until the late 1600's. This episode is set while Anne Boleyn is Queen which only encompasses 1533-1536 and is therefore over 150 years before the song was composed.
George Boleyn suggests his father would be "ipso facto" King. Whilst this is possible, it is more likely that he meant "de facto", since he would not actually be crowned, but acting as King.