Continuity mistake: When Xander is showing Willow and Buffy his fake ID and the view of the shot is from behind Xander, he is holding the card with his thumb and middle finger. Switch to the view from behind Willow and it's being held with his thumb and index finger. Then it switches to behind Xander again and it's back to thumb and middle finger.
Revealing mistake: When Faith is being chased by Buffy she jumps over a brick wall but as she does the wall wobbles.
Revealing mistake: In the scene where Giles and Ethan Rayne are drinking in the bar, the shots cut between Giles and Ethan frequently. When on Giles, you can see Ethan's hands/arms and his glass in the foreground of the shot, but almost every time the shot switches back to Ethan he's in a different position with no time to have moved. (00:14:40)
Continuity mistake: When the portal is opened Buffy crawls around to the other side of her bed yet just as the portal closes there is a wide shot and she isn't next to the bed.
The Freshman - S4-E1
Visible crew/equipment: When Buffy and Xander are doing some research, check the left side of the screen in a wide shot, when Xander asks "how far back do the disappearances go?" You may need to turn the brightness up, but there's a boom mike bobbing around. (00:34:25)
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: At the party where Riley is talking to Buffy by the stairs, when he first comes over there is no one in the corner on the stairs but in the next shot there are two people who disappear two shots later.
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: 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: In 'The Initiative', Riley, Graham and Forrest are looking in through the windows of Stevenson Hall with thermal goggles looking for Spike, they see him walking towards Willow. When we see Willow and Spike seconds later he is still sitting on the bed where he was for most of the scene. (00:37:30)
Revealing mistake: One of the arrows that Spike gets hit with passes through just below his left shoulder, but there are times when you can tell that it is a fake arrow because the part of the arrow sticking out at the front moves and the part at the back does not. Look at the arrow just after Buffy turns Hus into a bear.
Where The Wild Things Are - S4-E18
Visible crew/equipment: When Xander and Anya pull over in the ice-cream van, the front windscreen is very reflective. To avoid reflecting the camera crew, a giant screen was put in front of the ice-cream van - which, ironically, is reflected in the windscreen. It isn't a reflection of another vehicle parked in front of them as the thing that is reflected is a curved shape.
Visible crew/equipment: When Buffy, Willow and Anya are watching Looney Tunes, some stage lights are reflected in the globe behind Willow.
Visible crew/equipment: During the scene of the siege at Giles', there is a shot where an Indian guy jumps through the window and helps himself by holding on to the sill. If you look to the left side of the screen, you can see it's a moving wall and that several hands of crew members are holding it so it doesn't shake.
The Harsh Light Of Day - S4-E3
Revealing mistake: When Buffy is fighting Spike, she throws him against a table and then runs over it; you can see this is her body double. It is extremely obvious.
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.
The Harsh Light Of Day - S4-E3
Continuity mistake: When Spike is in the area where the gem is located, he walks to the right of entry hole, where he finds the gem. Then Harmony appears from the right side of the screen, where there's obviously no entrance.
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.
Answer: She has superpowers, ergo fast movement. The reason she outruns him so easily in "Touched" is that she stops trying to actually fight him and just dodges instead.
Shay