Funny blunder in Buffy, episode “What’s My Line” (2:9-10). Drusilla’s ritual needs to be at new moon; but as the sun is setting, she says, “The moon is rising.” (The new moon rises and sets with the sun.) [Later: In the same episode, Spike says “full moon”. So maybe I misheard elsewhen. Later still: I did not mishear; others have commented on the discrepancy.]
In the next episode, “Ted” (2:11), we see a blackboard in Jenny Calendar’s classroom – covered with snippets of BASIC code. Perhaps her brief possession by the demon Eyghon left its mark.
In “Bad Eggs” (2:12): Why does Sunnydale High have a room full of axes and hoes? Admittedly my school was small and didn’t have a lot of common hi-skool features (e.g. football), but I think I’d have learned by now if mining equipment were such a feature. — Also I’m fairly sure the word bezoar is misused.