Continuity mistake: In the episode "The Shroud," during the scene where Jack is talking to Daniel aboard the Odyssey, there is only 1 star on each of his shirt collars, indicating that he is a Brigadier General, instead of the proper two stars for a Major General, as he does in every other scene of the episode.
Plot hole: Huge plot error: Apophis and Clorell (Skara) should not have survived the explosion in Season 2, Episode 1 (when they attack Earth with two ships). In "Family" they explain that Apophis and Clorell survived by escaping through the stargate aboard Clorell's ship moments after Daniel Jackson did the same. However, when Daniel Jackson escapes through it, Apophis and Clorell are not even on the right ship, and there is 1 second left on the C4 timer when Daniel escapes. They actually show Daniel Jackson escape, and then cut to Apophis and Clorell still aboard their ship. So apparently, Apophis was able to "ring" from his ship over to Clorell's ship, make it to the stargate room, dial an address, and escape through the stargate all within literally 1 second. Is this guy related to The Flash?
Continuity mistake: Jacob Carter repeatedly mentions blending with Selmak 4 years ago, placing it in Series 4 (each season constitutes a year - when Carter leaves the SGC to join Atlantis at the conclusion of season 10, she talks to Teal'c about how they have spent 10 years together). However the blending occurred in Series 2 (6 years ago).
Factual error: The escort for Colonel O'Neill is wearing both Major and Staff Sergeant rank insignia. Probably what the writers thought was a "Sergeant Major", which does not exist in the Air Force. Major is a commissioned officer, sergeants are non-commissioned officers.
Continuity mistake: Daniel's interaction is inconsistent across the episode. Initially, Daniel emerges through the Stargate with no ripples in the event horizon or audible noise. Then he walks down the metal ramp making noise with each footfall. Later in the episode he returns through the Stargate with an audible noise and ripples in the event horizon. He remained "out of phase" for the entire segment of the episode.