The necklace that Spike takes off reappears and disappears between shots.
When Spike and Buffy first start their fight Buffy has both straps of her bag on her shoulders . After Spike first punches Buffy and we see her lying on the ground her book bag is not over both of your shoulders.
When Giles is talking to Buffy on the phone, he places his fencing sword on the bookshelf. Later, when he calls Buffy, the sword is back on his desk.
During the daylight fight with Spike, Sarah Michelle Gellar's stunt double is clearly evident several times, especially when Spike throws her forward towards the camera.
When Buffy calls Giles, his desk phone is clearly a rotary dial yet when Giles calls Buffy and the phone's face is turned away from the audience, his fingers move as if it was a touch tone.