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.
A New World - S3-E20
Factual error: Connor has been raised since he was a few months old by Holtz, a man with a British accent, in a dimension where there are no other humans. There is no possible way he could have an American accent, yet from the moment of his return he speaks with one.
Suggested correction: The demons in Pylea spoke English with American accents (possibly due to Wolfram and Hart's interference), and in tie-in comics, demons in the dimension Connor and Holtz went to were shown speaking regular English, though these comics were released years later.
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.
Factual error: Wesley has his throat cut, deeply enough to at least nick the artery (based on the amount of blood) and the windpipe (based on his difficulties breathing and talking later on), yet he somehow survives being left alone in the park for over 24 hours. In reality, he would have been dead long before then.
Sleep Tight - S3-E16
Revealing mistake: When Angel is seen gulping the blood from the cup (right before Lorne tells Angel that Connor needs some papa-love) you can see this is a special-effects cup (it's like one of those freezer mugs, where there's a layer of liquid on the outside). If Angel were really drinking out of the cup the way it's shown, he would have blood all over his lips and it would be running down his chin.
A New World - S3-E20
Revealing mistake: When Connor runs out of the hotel and Groo and Gunn drag Angel out of the sunlight, Angel's reflection can be seen in the door behind him just as Cordelia steps outside. Angel is a vampire: he should not cast any reflection.
Revealing mistake: When Groo rushes in to battle the tree demon, a cobweb gets stuck to the camera as it pans in.
Revealing mistake: Supposedly the demon Merl has no tongue, but when he is telling Angel the apology he wants, it can be seen. (00:01:00)
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.)
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.
A New World - S3-E20
Revealing mistake: The Axe that Groo throws at Conner at the start of the episode (Obviously CGI) doesn't match the movements of his hand, it leaves his hand before he actually throws it. (00:01:40)
A New World - S3-E20
Revealing mistake: The first stake that Conner fires from his stake cannon (Obviously CGI) doesn't seem to emerge properly from the barrel of the cannon, it emerges out of thin air from the side. (00:01:25)
Sleep Tight - S3-E16
Audio problem: At the end of the episode when Holtz jumps into the dimensional rift with Connor, we hear Angel yell "no" twice. But his lips don't move on either occasion.
Heartthrob - S3-E1
Revealing mistake: When James, a vampire, chases Angel and Cordelia into the subway, James' reflection is visible in the windows of a passing train.
Heartthrob - S3-E1
Revealing mistake: In this episode both Angel's and James' reflections are visible during the fight scene inside the train.
Benediction - S3-E21
Audio problem: When Cordelia has her vision about the vampires at the bar, her lips don't match the words "Vampires, a gang of them".
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)
Heartthrob - S3-E1
Character mistake: In the first flashback to Angelus and James in Marseille, Angelus briefly speaks with his modern-day American accent before reverting to his Irish accent.
