When the Gavrok spider jumps on Buffy’s back, you can see Nick Brendon laughing at Sarah Michelle Gellar in the next shot.

When Willow, who is being held captive in the Mayor’s building, stakes a vampire with a pencil, the pencil is nowhere near his heart.

Sarah and David’s stunt doubles can clearly be seen in the fight at City Hall.

When the gang is in the library looking at the map of City Hall, Buffy points to a location using her right arm. In the next shot, she’s using her her left arm.

Buffy takes her prom dress out of her bag (which is amazingly uncreased), then just leaves the bag full of weapons on the grass outside the school.

At the Prom, Wesley is holding a red napkin when he first spots Cordelia. The camera cuts to her, and when it cuts back to Wesley, he’s holding a yellow napkin.

When the hellhound bursts loudly through the window of the store, “Tux Boy” keeps calmly adjusting his tuxedo right up until he is attacked.

While the group is discussing the Prom in the Library, there is a close-up shot of Giles, and a small pile of books on a cart near the cage. In the longer shot there are more books on the pile.

When Faith and Buffy are fighting on the balcony, Faith falls on some cement and gets quite a bit of white dust on her bottom but it’s gone when she breaks out of her handcuffs.

Buffy and Faith’s stunt doubles can be seen in their big fight at Faith’s apartment.

When Angel is in the library, we see his face is sweaty, but from the side it looks dry.

When Angel is talking to Buffy, he holds a box in two hands which changes to one hand in the next shot.

Angel’s reflection can be seen in the picture frame when he leaves the Professor’s apartment.

At the end, when the gang are discussing the battle, there is a couple walking down the pavement, away from the group. The camera does a few close-ups and when it cuts back to the far-away shot, the couple is still walking close to the group.

Angel’s stunt double can be seen clearly after Xander orders the kids to fight “hand to hand”.