Seeing Red - S6-E19
Continuity mistake: When Buffy is fighting Warren at the end, there are several shots when it's clear that it's a stuntman playing Warren. The stuntman is taller and slimmer than Adam Busch, and the shape of his face is different, as is his hair in the front.
Continuity mistake: Near the start of 'The Wish', the scene where Cordelia is talking to the Cordettes and meets Anya. During the close-ups of Harmony, Anya is standing to camera right of the brunette Cordette behind her. A few seconds later when the shot is further away Anya is standing camera left of the Cordette. (00:05:40)
Continuity mistake: During the opening of the season 6 episode "Grave," Willow's nose starts bleeding and she gets blood on her upper lip. Over the next several shots the blood consistently keeps appearing and disappearing.
Nightmares - S1-E10
Continuity mistake: In the season 1 episode "Nightmares", Buffy is talking to Willow about her mom's divorce and she shuts her locker. A few seconds later she shuts her locker again. (00:02:55)
As You Were - S6-E15
Continuity mistake: When Buffy receives her letter from UC Sunnydale it says her address is 1630 Crestview, this doesn't sync up continuity-wise with the episode The Body as she tells the 911 operator that her address is 1630 Revello. She didn't move so it's a definite mistake.
School Hard - S2-E3
Continuity mistake: While studying at the Bronze, Buffy and Willow leave their books on the table to go and dance. Spike calls them outside to fight a vampire, and when Xander runs back inside to grab a stake the books have all been put back into Buffy's bag. (00:14:00 - 00:15:45)
Continuity mistake: When Buffy finds Dr. Gregory's glasses on the lab floor she places them on the table, from the long shot she places them at the left end of the table near a plastic tub with a white lid, with the glasses open. Then it cuts to a close up where they are in front of a book on the right side of the table and are closed. Then cut back to the long shot and they are in the original place. (00:10:25)
Continuity mistake: When Riley is dressing Buffy's wound, it is much further to her left side than where she was actually staked, which was more central on her stomach. (00:00:35 - 00:02:40)
Revelations - S3-E7
Continuity mistake: When the female watcher is being destroyed after Buffy cuts off her arm. Her sleeve is empty, which is not possible, as Buffy could not have removed the arm but not the sleeve. Also the arm on the floor is removed at the elbow, but the watcher has lost the entire arm in a previous shot.
Continuity mistake: The book that Cordelia replaced sideways in the bookshelf behind her disappears, and then reappears just before she and Xander kiss.
Seeing Red - S6-E19
Continuity mistake: When Tara got shot, the blood on Willows shirt was spread out, but in the next shot, there were big clumps of blood.
All The Way - S6-E6
Continuity mistake: When a vampire kicks through a car window trying to hit Buffy, some shards are still standing in the window frame. The angle changes, and the shards are gone. (00:37:00)
Continuity mistake: When Buffy is walking forwards through Angel's dust in 'The Wish' there's a vampire running towards her, only a few steps behind. Then there's a shot of her walking forwards taken from another angle, then when we can see behind her again the same vampire hasn't moved forwards at all, he's still running from 3 steps behind her. (00:41:25)
Tough Love - S5-E19
Continuity mistake: In season 5, 'Tough Love', Glory crushes Tara's hand causing her blood to drip onto the bench. In later shots however, there is no blood on the bench, it is clean. (00:25:40)
Continuity mistake: In the episode 'Empty Places' when Xander is returning from hospital Kennedy is standing beside the couch to greet him and Willow. When Xander sits down she is sitting on the couch, but she wasn't out of shot long enough to have gotten there.
The Harsh Light Of Day - S4-E3
Continuity mistake: When Spike finally gets into the area where the gem is and Harmony follows him up there, he puts on that necklace thinking it's the gem. When he realizes Harmony has the gem it shows him taking off the necklace. It cuts to another shot and then shows him again with the necklace, but minus the charm.
Continuity mistake: Drusilla kills Kendra by cutting open her jugular artery and leaving her to bleed to death. When Buffy enters a while later, there is not a drop of blood anywhere. (00:41:40 - 00:42:45)
Continuity mistake: When Buffy drowns in Prophecy Girl, she falls into the pool with her hair tied in a ponytail and her arms under her. When she is discovered by Angel and Xander, her arms are by her sides and her hair is loose. (00:33:55)
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.