Plot hole: In the scene where Ba'al goes through the stargate and arrives in 1939, the event horizon from the stargate puts a hole in the haul of the ship. Later when SG1 goes through the stargate the hole is covered with ice. The event horizon created from SG1 would have been the same as the previous one and removed the ice from the hole.
Continuity mistake: The first time the Achilles is attacked, Cam's relative does not leave the bridge until after Baal gates in. However the second time when Cam is there, he appears as Baal is gating in.
Suggested correction: And the second time, since Cam is now there, the timeline can/will have changed, so something about Cam's presence may have caused him to come down sooner.
Factual error: When Cam ambushes Ba'al in 1939, he has two Thompson M1 submachine guns. The M1 version of the Thompson wasn't developed until 1942.
