Continuity mistake: After Xander and Oz's "Kryptonite" conversation, Buffy tosses a book onto the table and stands up to leave. The book lands partially on top of another book and slides almost off it. In the next shot the book is lying on top of the other book perfectly.
Plot hole: When Buffy enters the house to rescue her mother she uses a stake to stop the front door from closing. A vampire then grabs it and the door closes. Why did Buffy use a stake knowing that there was a vampire there when she was almost killed by a vampire with her own stake earlier in the episode because Giles had been injecting her with a muscle relaxant?