During the fight outside Kahlest's home, one of the assassins gets in a shot on Picard's right cheek. However, for the rest of the episode, he has a bruise on his left cheek.
As Worf enters the great hall, his sash is snug and fastened. The moment Duras rips it from him, you can see the sash is slack and has been prepped for easy removal.
K'mpec gives a command in Klingon - something akin to "in my chambers!" after Kahlest is brought in as a witness. His mouth doesn't move when he gives the command.
When Picard asks Kahlest if Mogh was a traitor, she responds, "No, Mogh was loyal to the Emperor." She should have said "Empire", as it is explained in Rightful Heir (1993) that there had been no Klingon Emperor for three centuries at this time.
[ca 15:37] Picard gives the order to "set coordinates for the First City of the Klingon Imperial Empire." This is redundant, as "Imperial" is an adjective meaning "of or relating to an empire."
When researching Kahlest, the Enterprise computer screen text states that she was transferred from the Intrepid to Starbase 23. However, Dr. Crusher says "Starbase 24".