Other mistake: When Buffy is talking about Spike's trigger she says, "He's a bomb and I need to know how to defuse him." The DVD subtitles misspell "defuse" as "diffuse." (00:23:55)
Other mistake: When Buffy pulls the knives out of the Bringers, there is no blood on them. Also, you can see the muscular arm of Buffy's stunt double pushing the knives into the Bringers. (00:34:00)
Other mistake: When Robin Wood is burying Jonathan, Jonathan's face flinches when the first heap of dirt lands on his legs.
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.