The line "See what you get for taking French instead of Sumerian?" was changed from "See what you get for taking Spanish..." after Nicholas Brendon remembered established continuity.
One of the pieces of "high tech laboratory equipment" in The Initiative's hideout is a DJ mixer, which can be seen when Spike is slammed into by Forrest.
The DVD commentary states that the "super-Buffy" was inspired by the comic book heroine Promethea.
Xander tells Col. McNamara, "Great plan. That's right up there with 'duck and cover'." From the early 1950s through the 1960s a lot of Americans believed nuclear warfare was inevitable, and imminent. Children were trained that if they ever see a distant bright flash of light, they had only a couple of seconds to react. At school we had drills where we ducked under our desks and covered our heads. In the open we were supposed to hit the ground and curl up. None of these moves would really help anyone survive a multimegaton nuclear blast.
The invocation of the First Slayer has serious consequences in the next episode and in subsequent seasons.