Buffy the Vampire Slayer

During the Mayor's speech, the tassel on Buffy Graduation cap is on the wrong side. Every other student's is correct.

When Buffy is in a coma and the mayor is choking her, you can clearly see that his hand is only covering her mouth, leaving plenty of room for Sarah to breathe through her nose.

As Buffy runs to a doorway into the school with the Mayor chasing her she runs down a covered walkway that has widely spaced support columns. The scene changes to an interior shot as Buffy enters through the doors and now there is a concrete wall with sculptured openings in it outside the door that wasn't in the exterior shot.

In the end battle scene between the Students and the vampires, just as the school blows up, Cordelia can be seen hiding in Jonathan's shoulder. This is a strange thing to happen as Cordelia and Jonathan never really get along, and Cordelia treated him quite badly throughout the series. However- according to Danny Strong in the season three featurette, Season 3 Overview- this scene was an idea of Charisma's, because she wouldn't see Danny again for a long time and she never got much screen time with him.

When Buffy awakens from her unconsciousness in the hospital, she approaches Faith's bed and returns the forehead kiss that Faith had given her towards the end of the episode "Enemies."

Principal Snyder is killed in this episode by being eaten [by the Mayor in demon form]. This, after Snyder made such a big deal back in "The Puppet Show" (Season 1, Episode 9) about how former Principal Flutie was a loose and easy-going principal which was why "he was eaten" ("The Pack" - Season 1, Episode 6). Are we to draw the same conclusions about Snyder's abilities as a principal? or is it just funny irony? Either way, Whedon has a knack for making clever links between episodes.

When Buffy hits Angel for the last time and he vamps out, you can see that he's already done it before the sounds effects and he turns back to look at Buffy (meaning he was vamped before Buffy hit him that last time).

The Mayor says during his speech that Sunnydale is celebrating it's centennial. But on the "Welcome to Sunnydale" sign Spike ran over in "School Hard" and "Lover's Walk" it said that Sunnydale was established in 1909, making it 90 years old, not 100.

During Cordelia and Wesley's awkward kissing scene she pauses and her hand is down by Wesley's waist. They change angles and it is on his throat.

Look closely during the final battle, and you can see some students smiling and obviously enjoying their time on the camera.

When Cordelia stakes the vampire during the graduation battle, she uses no force in her attack. Since she is not a Slayer, it does not seem likely that the stake would be able to break through the Vampire's clothes and rib cage.

When Angel brings Buffy into the ER room, there's a security guard positioned outside. The guard can be seen when Angel steps into the hall to call Giles and Co. But when the Mayor and Angel get into a skirmish in Buffy's room a few minutes later, the nurse calls for security and nobody comes. The guard couldn't have gone that far.

When Angel takes Buffy to the hospital after feeding on her, he bursts through the doors of the ER carrying Buffy in his arms, but you can see that Sarah is still holding on to his shoulder from when he just picked her up prior to the start of the scene. As he moves through the ER, Sarah realizes she's supposed to be unconscious and relaxes her hold on him to let her arm just flop naturally.