Obvious stunt double for Gowron during the fight scene.
Kira orders "thrusters ahead full" but as the ship is shown from the outside, the ship is moving backwards.
During the fight near the end, Worf is thrown through a glass partition. The glass breaks before he makes contact with it.
When Odo disguises himself as the Female Changeling, he is able to mimic the exact progression of the morphogenic virus that she is suffering, despite not having seen her since she began displaying symptoms.
The Cardassian uniforms are meant to be partly metallic, yet Gul Rusot's is shown bending like rubber after his fight with Kira.
When Worf drops his combadge on the table, the sound of it striking the table occurs before it makes contact with the table's surface.
Worf wins leadership of the Klingon Empire from Gowron, but turns it over to Martok. By Klingon law, Worf would be recognized as the new Chancellor due to his defeat of Gowron. Martok has no claim to leadership and would not be recognized as leader.
Damar was previously the leader of Cardassia and is now the face of the rebellion movement. He is too recognizable to successfully pull off an undercover mission. He would likely be recognized instantly, and was. It was only luck that the Cardassian who recognized him was sympathetic to his cause. He could have just as easily encountered a Cardassian who was loyal to the Dominion, or a Vorta, Jem'Hadar, Breen, or Changeling who knew his face.
Kira hands Damar her headset and tells him to "take the helm." The headset acts as a viewscreen and communications device. It does not confer helm control.
When discussing their plan to capture an operative of Section 31, either Sloan or someone else, Bashir and O'Brien repeatedly refer to this hypothetical captive as "he." Since they are fully aware it may not be Sloan himself who shows up, there is no reason for them to assume the gender of the agent they lure in. Section 31 could very easily have female, non-binary, or even non-human operatives.