Continuity mistake: When Xander falls through the ground, he lands with his arm on, or very near a bit of wood, but in a closer shot of him just before he gets up, the wood's disappeared and other rubble has moved around too.
Continuity mistake: When Buffy and Willow are talking about the sham of Thanksgiving Day at the groundbreaking ceremony, on one angle (the one where Buffy's face is shown) there is a strong wind blowing, moving their hair about, but in the other (when you can see Willow's face) their hair aren't moving.
Continuity mistake: In the scene where Anya is undressing a sick Xander in his basement, she lifts up his shirt and says 'Help me get your trousers off.' During the following conversation, in the close-up shots his shirt is lifted far up on his chest, but in the wider shots it's covering his whole stomach.
Continuity mistake: The first night that the Gentlemen float through the college, they are on the 2nd floor one minute (all the room numbers start with 2), then they turn a corner and are suddenly outside room 118, a floor below.
Continuity mistake: Near the end, when Spike takes the cup of blood from the fridge, we can see that it is full to within a 1/4 inch of the rim. However, when the shot changes and he drinks it, he tips the cup almost 45 degrees before putting his lips to the cup and drinking. If the cup had been as full as previously shown, the blood would have begun pouring out long before Spike ever drank form it.
Continuity mistake: In the season 4 episode "Doomed," during the fight at the Hellmouth, Willow throws the sack of bones to Spike, who catches them and looks startled. In the very next shot of Buffy fighting one of the demons, Spike can be seen in the upper left corner of the screen, with empty hands, quite calmly watching the fight. (00:36:35)
Continuity mistake: In every other episode it's seen in, room 314 is a room directly off a corridor, but in "The I In Team" Walsh walks through the door off the corridor, then there's another shot of her walking through a door. Where did the second door come from? (00:13:50)
Continuity mistake: At the end of the episode, as Spike's getting his T-shirt on, from one angle he gets his arm completely through a sleeve, then we cut to a different view and he's still pulling it on.
Continuity mistake: The first shot of Maggie Walsh being impaled from behind with the skewer indicates that there is no one standing close by, judging by the amount of negative space around her. However, following shots reveal that the skewer is coming straight out of Adam's wrist, therefore he should have been visible in the previous shot.
Continuity mistake: When you first see Adam lying on the bed, before he wakes up you see his human side of his face on his right side. In the next scene the camera is over Maggie Walsh's shoulder and the human side of his face is now on the left side. Then just after he stabs Maggie it switches back again.
Continuity mistake: When Buffy is talking to Riley, she puts the scarf on her head, on his hand. He talks to her and says "Maybe I am the bad guy," and in the next frame her scarf is back on her head again, then off again in the next frame. (00:24:20)
Continuity mistake: When Faith is waking past the movie theater, the same couple passes behind her in 3 identical shots. (00:19:29)
Continuity mistake: In 'This Year's Girl' when Faith is taunting Joyce with all Buffy's uncollected mail she flings the envelopes across the bed one by one, scattering them. When Faith is fighting Buffy later on they are all in a pile again. (00:37:20 - 00:38:40)
Continuity mistake: When Buffy and Riley are in Buffy's room, Buffy holds Riley's hand with both of her hands and says to him, "Is there anything I can do?" But in the following shot she is holding Riley's hand with only one of her hands.
Continuity mistake: In the scene near the end when Faith is putting Joyce's lipstick on in the mirror and taunting her, it is obvious that the make-up department forgot to put Faith's tattoo on her upper arm. It's obvious if you watch back and forth between the mirror and the shot of Faith standing and turning, there is no evidence of a tattoo that has been established Faith has in the previous season.
Continuity mistake: When Adam enters the cave and is talking to the vampires and then pulls the head off of one of them, watch as he falls, his head is still visible when he is falling out of frame. (00:15:25)
Continuity mistake: After the group find out Jonathon cast a spell, Willow is holding a book to her chest. But in the side shot, the book is resting on her stomach and then back on her chest a few shots later.
Chosen answer: He had larangitis and because of the shooting specifications they had to have him shoot the scene with a bad throat, they then re-recorded his lines and dubbed them. At various points during the scene and indeed the episode you can see him touch his throat or rub it.