Continuity mistake: When Xander chugs the martini Miss French gave him, the way he's holding the martini glass changes instantly between cuts. First he's holding it by the top, then he's holding it by the stem, then he's holding it by the top again.
Continuity mistake: When Buffy and Angel get to Buffy's house at the beginning, Buffy starts to use a first-aid kit to patch up Angel's wound. Angel's arm goes from down by his side to up on Buffy's shoulder between cuts. (It can be hard to see since it's close to the bottom of the frame, but it's noticeable. It seems like they cut out a few seconds to quicken the pace.) She's also a little bit closer to Angel between the same cut.
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: When the Scoobys are in the cafeteria in the beginning, Xander asks what the "green stuff" is in a wideshot, and it cuts to a closeup of Buffy. In both shots, you can see two extras in the background doing the exact same thing twice - walking from screen-left to screen-right, while one of them distinctly lifts their tray up for a moment. The extras were probably just told to repeat the same actions in different takes to populate the background, leading to this odd mistake.
Continuity mistake: After Xander chugs his martini, he transfers the glass to his left hand. But then, it's back in his right hand instantly between cuts.
Continuity mistake: When Miss French scoots closer to Xander and asks if he's ever been with a woman before, Xander hands go from being apart touching between cuts.
Continuity mistake: After Giles closes the library for "filing, " we see Buffy grab a crossbow off a shelf. It is upside down when she grabs it. Instantly between cuts, it is right side up. You can tell from the grip thingy that sticks out from it. (It looks like she starts to rotate it in the first shot, but it's instantaneously flipped over in the next).
Audio problem: At the beginning of the episode at the Bronze, when Buffy gets up to go and Willow tries to get Buffy to stay, Xander suggests they can dance. But his mouth movements don't match the words when he says "Eh, yeah, it's early..." (His head is turned away from camera, but you can see the side of his mouth, and he's saying something else).
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: When Borba reawakens at the funeral home and says "I have been judged, " you can sort-of see Owen reflected in the glass in front of him, and Owen's face looks totally blank. When it cuts to Owen, Xander and Willow (right before the commercial break happens), Owen suddenly has a shocked expression on his face.
Never Kill A Boy On The First Date - S1-E5
Deliberate mistake: When Buffy and Giles are searching the funeral home, we see three shots of Buffy and Giles opening up different mortuary-cabinet doors, shot from the point of view of the cabinet. The problem? You can tell they're opening and closing the same door over and over again. The background is exactly the same, and all they've done is slightly re-arrange the stuff behind them, and had the actors come in from different angles to create the illusion they're opening different doors. It's SUPER obvious.
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: When Buffy introduces Owen to Angel, Buffy starts to scoot towards Owen but is still a good foot away. However, when the shot cuts, suddenly she is pressed right up against him.
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: During Buffy and Owen's date at the Bronze, after Buffy shoos away Cordy, Buffy turns and smiles at Owen. In the first shot, she's smiling with a closed mouth. Suddenly in the next shot, she's open-mouth grinning with her teeth exposed.
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: After the crash, when the bus driver walks up to the vampire that he hit and asks "Can you move?" the blood that was on the right side of his forehead in the previous few shots vanishes.
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: The second time we see the van going to Sunnydale, the creepy guy is delivering a weird sermon. At one point, we see him reflected in the driver's mirror, and he is gesturing with his right hand, which is up around his abdomen/chest area. It then cuts and suddenly his hand is down by his side.
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: The second time we see the van going towards Sunnydale, the creepy religious zealot guy puts his arm on the seat behind the mother and child. It then cuts to a closeup of them, and we cannot see the creep's arm behind them. It cuts back to a wideshot, and suddenly his arm is behind them again.
Never Kill A Boy On The First Date - S1-E5
Visible crew/equipment: When Buffy and Giles are in the cemetery, right before Buffy bails to go meet Owen, you can blatantly see a number rectangular studio/set lights reflected in Giles' glasses coming from various angles. (There wouldn't be dramatically-angled lights like that in a cemetery, let alone after dark).
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: When Buffy gets up to walk over to Owen in the cafeteria, watch Willow and Xander... the directions they are facing change when it cuts to the wideshot. They suddenly are both watching Buffy in the wideshot, which they weren't before the shot cut. It's pretty subtle, so you have watch closely to notice.
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: When Buffy, Xander and Willow are in the cafeteria in the beginning, Buffy says she's going to sit with Owen and Willow tells her "good luck." The way Willow is holding her fork changes between edits. (Specifically, it goes from pointed down to pointed up between cuts).
Never Kill A Boy On The First Date - S1-E5
Continuity mistake: When Buffy stakes the vampire in the opening scene, his arms go from up in the air to down by his sides between cuts right as she stakes him.
Continuity mistake: When Giles and Buffy are talking about how to kill the She-Mantis, around the time Buffy says "Slice and dice!", her hands go from down by her sides to up in front of her chest gripping together between cuts.
Audio problem: When Xander is talking to Blaine in the cell, Blaine is explaining what Miss French/She-Mantis does. At one point Blaine says "She ties you up, " but his mouth doesn't match the words at all. His mouth and the words match for every other line, so I'm assuming they decided to add that line in post.
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.