I Only Have Eyes For You - S2-E19
Factual error: In the episode 'I Only Have Eyes For You', during the flashbacks to 1955 James and Grace dance, and James later shoots himself, to the song 'I Only Have Eyes For You', which wasn't released until 1959. (00:18:20 - 00:26:50)
Children of the Gods (1) - S1-E1
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.
Wax Doll Castle Murder Case: File 3 - S1-E9
Factual error: The culprit merely drops a chandelier from the ceiling in an unplanned move. From that simple action, the whole building - a huge castle - catches fire so quickly you'd think it's made out of papier-mâche soaked in gasoline, not stone.