Continuity mistake: When Buffy comes in to talk to her mum about the CAT scan, we hear her shut the door behind her. We then cut to a shot of Buffy, and can see the door slightly ajar in the background. (00:10:30)
Continuity mistake: When Joyce is talking to Buffy about the shadow, after she says "sometimes weeks", she turns towards Buffy. In the next shot she's facing away from her, then turns to face her again. (00:10:55)
Revealing mistake: When Glory creates the demon snake thing, we see a CGI image of the creature, but Glory and Buffy are nowhere to be seen. When we are shown where they are standing, their position should have been visible when the snake demon was created. (00:27:05)
Visible crew/equipment: When Giles picks Buffy up in his car, you can see lighting and camera equipment on the right.
Audio problem: At the start of the episode when Buffy and Dawn are with Joyce in the hospital room, Dawn starts eating jelly, and when Joyce starts speaking you can see in the left hand corner of the screen Dawn talking, but no words are coming out.
Character mistake: Willow refers to the Tunguska Blast of 1917. However, that event actually occurred in 1908.
Continuity mistake: When Buffy, Dawn and Joyce say goodbye to Doctor Kriegel after being given Joyce's medication, the position of Dawn's hair changes between shots.
Continuity mistake: In the end of the scene where they find the dead mental patient killed by the meteor alien, the group walk away from The Body leaving Riley still there, but Anya's coat can be seen in the bottom left corner after she had walked away.
Plot hole: How did Buffy know where to find Riley at the end of 'Into The Woods'? He told her he was leaving with the army, but he never mentioned the helicopter pad. (00:40:30)
Visible crew/equipment: In the episode "Into The Woods" at the very end you see shots of Buffy and Riley from both the helicopter and the ground. The 2nd shot of the helicopter you can see a camera in the top right corner of the chopper. (00:40:35)
Continuity mistake: When Buffy is hitting the punching bag near the end of the episode and Riley comes in she has bandages wrapped around both her hands but in the close up shot there is only a bandage on her left hand.
Plot hole: When Buffy talks to Xander at the end and he tells her to stay with Riley, she mentions that he is going at midnight. But earlier in the episode, Riley doesn't tell Buffy he is going at midnight, he says "Transport's leaving tonight" first, and at the end of the conversation he says "Unless you give me a reason to stay, I'm leaving tonight". Nowhere in this episode does he tell Buffy that he's leaving at midnight.
Continuity mistake: After Riley stakes Spike and Spike decides to drink, he is shown opening the bottle. The camera shows Riley and then goes back to Spike. Spike is holding the bottle, lid still on, then he goes to open it again.
Continuity mistake: In the season five episode Triangle, Anya says she has never driven before, but in Graduation Day part one she tells Xander she has her car right outside. (00:22:50)
Visible crew/equipment: In the final scene in the Magic Box where Buffy cries, in several shots of Buffy you can see, in the right of the shot, the sleeve of a white shirt, which none of the characters are wearing.
Checkpoint - S5-E12
Continuity mistake: In the series 5 episode 'Checkpoint' when Buffy has just accidently axed the dummy, watch her blindfold. It goes from being pushed up above her forehead on her hair, to being right down by her eyes. This changes between every shot. (00:27:55)
Blood Ties - S5-E13
Continuity mistake: In the first scene of the episode, just after the teaser, the Scoobies are gathered around the table at Giles' magic shop. During the second part of the scene, we can see Anya is alternatively lying her arms under or above the table depending on the camera angle, whether from behind or facing her. (00:01:55 - 00:03:15)
Blood Ties - S5-E13
Continuity mistake: When Ben brings him and Dawn some hot chocolate, the cups containing the hot chocolate are in fact two cups, one inside the other, making a total of four separate cups. But once Ben reveals that he is in fact Glory, Dawn's two cups have suddenly changed to just one cup.
Revealing mistake: When the porter is dragged back onto the train at the start you can see (more obviously if you watch in slow motion) that there's absolutely nothing grabbing him, not even someone's shadow. (00:04:55)
Chosen answer: Angel is saying that he is still jealous and Buffy recognizes that this is his way of saying he wishes that they could be together. That is why they both smile.