Moore said that Billy was killed in "Sacrifice" because Campbell was being offered good roles on other television series, and the scheduling conflicts were interfering with filming. The writers found it implausible that Billy would simply quit as Roslin's chief of staff and could not think of any other good excuses for the character to be missing from the narrative for long stretches, so they decided to kill the character. Moore called Campbell's departure sad and said in his podcast commentary, "It's not something I thought we'd be doing when the season began." Campbell said in an interview that he was not surprised by the decision. He said that he was unwilling to sign a five-year contract, and the producers concluded he was not committed to the series.