Buffy may have been killed after she was shot by Warren, as she flat-lined right before Dark Willow removed the bullet and sealed the wound. If so, this would have been her third death, following her respiratory failure in Prophecy Girl (1997) and her self-sacrifice in The Gift (2001).
However, it was already established that Willow could not raise someone from a "natural" death when she attempted to do so with Tara, whose death came from a gunshot in the exact same scene where Buffy got shot. Had Buffy been dead from her own gunshot wound, Willow's removing of the bullet and reviving her wouldn't have been possible any more than it was possible to resurrect Tara.
However, it was already established that Willow could not raise someone from a "natural" death when she attempted to do so with Tara, whose death came from a gunshot in the exact same scene where Buffy got shot. Had Buffy been dead from her own gunshot wound, Willow's removing of the bullet and reviving her wouldn't have been possible any more than it was possible to resurrect Tara.
This is the third time that Willow has caused a deity pain by harming Osiris, with the first two being in her two fights with Glory in Tough Love (2001) and The Gift (2001).
Amber Benson is removed from the opening credits, only one episode after joining them, and also makes her final appearance in the series.
Xander says "out of the mouths of babes" after a comment made by Dawn, which is the same line said by the Master after a similar comment made by the Anointed One in Angel (1997), both referring to murder.
Clem says, "I was just about to make some Country Time", referring to the American lemonade product.