Charisma Carpenter turned down their initial offer to appear as Cordelia (she revealed years later that she didn't want to work with Joss Whedon after years of constant harassment and verbal abuse, and firing her for getting pregnant the previous season). She said she later agreed to come back in order to give fans some closure to the character.
According to Charisma Carpenter, she and David Boreanaz spent several hours crying together during their finale scene.
Christian Kane says he had a difficult time calling himself 'Doyle' because he felt on some level he was masquerading as deceased Glenn Quinn. "It was a very awkward situation for me and David because we were close to Glenn," says Kane. "I didn't know how the fans were going to react to it." Kane says the memory of Quinn upset David Boreanaz: "I could see it in his eyes... it's got to be a tough deal for him." However, Kane thinks that "Joss is brilliant because he used that. How do you turn me and David against each other? You really can't because we're such close friends. So to use that for Angel and Lindsey, I think has a little bit of brilliance to it. It's kind of sick...but it did the job." David Fury adds, "I think [the fans] appreciated it from the standpoint that we were honoring him. That Doyle's not a forgotten piece of this world."
David Boreanaz, Charisma Carpenter and Christian Kane are the only actors to have appeared both in this and the first episode City of... (1999).