Disharmony - S2-E17
Continuity mistake: When Cordelia and Harmony are on the couch talking and drinking, the towel on Cordelia's head goes from on her shoulder to behind in the change from wide to close up. (00:10:30)
Disharmony - S2-E17
Continuity mistake: When Harmony enters Cordelias bedroom, the strap on Corelia's shirt falls off her shoulder and then magically is back in place after the angle change. (00:13:50)
Disharmony - S2-E17
Continuity mistake: In 'Disharmony' Willow's hair is over her eye when she says "Thanks for the affirmation", but when we see her again a second later its tucked behind her ear. The shot wasn't on Cordelia long enough for her to have tucked it back. (00:16:45)
Disharmony - S2-E17
Continuity mistake: In some of the shots in the scene with the red bird, it is raining and in some shots it is not.
Disharmony - S2-E17
Continuity mistake: When Angel pulls Cordelia aside and says that Harmony cannot work with them, a man in the background walks past in the shot of Cordelia but we never see him walk past in the shot of Angel.
Through The Looking Glass - S2-E21
Continuity mistake: When Angel transforms into his inner beast for the first time he is seen ripping off the right leg of an Imperial guard, but in following shot the leg is intact and it stays like that for the rest of the fight. (00:25:35)
Heartthrob - S3-E1
Continuity mistake: In the scene where Angel has just returned and given Cordelia her necklace, watch Cordelia's hands; they keep changing position in each shot. In one shot she is trying to put the necklace on, in the next shot she appears to have given up and brings her hands down and bundles the necklace in her hand. Then when the shot changes to behind her, she is trying to fasten the necklace behind her neck again. This happens a few times during this scene.
Carpe Noctem - S3-E4
Continuity mistake: When the gang rescues Angel and returns him to his normal form towards the end of the episode, Cordelia shocks him unconscious with a taser and he falls to the floor, lying on his front. But when Fred whacks him on the head with her baseball bat, he is suddenly lying on his back.
Quickening - S3-E8
Continuity mistake: Sahjhan establishes that he is incorporeal on Earth, but when he takes Holtz to meet his demon minions, he manages to knock on the door.
Continuity mistake: When Lorne covertly warns Angel that the hotel is bugged, he places a note in Angel's pocket with his hand on Angel's shoulder. When Wolfram and Hart watch the video feed later, the hand that was on Angel's shoulder is now in front of Angel's chest. (00:22:50 - 00:37:00)
Continuity mistake: When the demon Angel and Groo are chasing crashes through a wall, the resulting hole lets in enough sunlight to force Angel into the shadows. A few shots later, Wesley notices Angel standing in the entrance to the hole. Only a few moments have passed, so Angel shouldn't be able to stand where he is. (00:15:20 - 00:16:20)
Sleep Tight - S3-E16
Continuity mistake: Right before Holtz and his men arrive at the hotel, Angel arranges three of Connor's toys in his cot. One of them is a teddy bear which he places in the middle of the cot. But once Holtz and his men arrive, the teddy bear is suddenly at the far end of the cot resting on the pillow.
Continuity mistake: The entire area around Cordelia and Skip is supposed to be frozen in time. However, there is a car driving freely across a bridge in the background behind Cordelia. (The background is blurred, so it is difficult to see.)
Continuity mistake: When Angel is talking to Cordelia in the garden at the very end of the episode "Supersymmetry" he has a cut on his cheek. The beginning of "Spin The Bottle" is the continuation of that scene, but Angel's face no longer has a cut.
Continuity mistake: After Cordelia kisses Connor, her hand is on his cheek. Just before she says "and if this is the end", in the shot of Connor she removes her hand, then the angle changes to show her, and her hand's suddenly back on his cheek again.
Continuity mistake: When Angel grabs Cordelia's hand as she apologies after telling him to "get over it", the position of Angel's hand changes between shots.
Continuity mistake: When Cordelia looks at the monitor, the reflection of Angelus's cage shows Angelus standing at the bars next to Connor. It cuts to a direct shot, and Angelus is sitting on the ground on the other side of the cage. (00:21:40)
Answer: Due to his epiphany, Angel basically had the 'true darkness' he worked so hard to reattain ripped away from him, like his soul was after sleeping with Buffy.