Never Kill A Boy On The First Date - S1-E5
Other mistake: In the famous scene where Buffy tells Giles, "If the Apocalypse comes, beep me," she grabs her pager from out of shot. Trouble is, she's standing in the middle of her hall and there's nowhere she could have picked the gadget up from. (00:21:00)
Other mistake: Willow's computer beeps twice when her first email from Malcolm is received through before she is kidnapped by Fritz, but only beeps once when the second email is received.
Other mistake: When Sid gets into Buffy's bed and Buffy screams, her mum immediately comes into her room to find out what's wrong. Now, unless she sleeps on the landing, Buffy's mum is really quick at getting out of bed.
Other mistake: In the very first shot (a long tracking shot backstage), watch the girl practising with her tuba. At one point she pulls her mouth away and then leans back in and starts playing some notes. But you can tell that she isn't blowing into it, and in fact, her mouth isn't even quite touching it. So it shouldn't be producing any notes. Then, almost immediately after, you can also see the actress purposely moving the tuba (sort-of rotating it to her right) to get out of the cameraman's way.
Other mistake: The Master's skeleton, before it is destroyed, looks to be female and not male. (Note the wide hips and large birth canal-like hole.) Also in the Next season's "When She Was Bad," they have another shot of the same skeleton, however the hips are much smaller and more male. (00:43:55)
Chosen answer: "So goes the nation" seems to have been used on many occasions, with various different US states in the "As .... goes" section. Most commonly it seems to be California that's considered to lead the way, but probably most other states have appeared in the lead role at some point or another. Other things have also been used - no less a person that Pope John Paul II said "As the family goes, so goes the nation...". The origin of the quote format is unclear - in US politics it goes back into the 19th century, when it was Maine that held the title spot, but, while no definitive origin is known, it seems highly likely that it goes back considerably further than that.
Tailkinker ★