When Dawn leaves the principal's office, she leaves her bag there. In the next scene, Dawn is walking with her bag.
When Buffy rescues Dawn from the railway tracks you can see she jumps from a standing start at a point next to the tracks.
When Buffy is saving Anya from the demon in her apartment, Anya can be seen lying on the ground when the focus is on Buffy but then she is shown crawling again.
Before Xander and Spike ambush R.J., you can see Spike's reflection in a storefront window.
When Buffy is watching the principle talk to RJ, you can see a hand on her cubicle wall at the left of the screen.
At 5:11, as Anya is walking to the refrigerator, she passes a stove with a glass-fronted oven above it, and in the glass you can see the reflection of the cameraman and his assistant.
Dawn walks out of the principal's office without taking her bag off the back of the chair.