When Starbuck tackles Number Six and they fall off the ledge, Number Six is shown holding the arrow in her hand when they impact the floor. It is later shown to have (presumably) been thrust through her chest as if she landed on it.
When the fight between Starbuck and Number Six ends they fall from a ledge. When Helo helps Starbuck off of Number Six, it is seen that Number Six is impaled by a piece of rebar that sticks a good 6-10 inches from her chest. Since Starbuck landed flat on Number Six, Starbuck would have also been impaled.
A camera man in a red shirt is clearly visible behind the Arrow of Apollo display case seconds before Starbuck shoots the glass.