Continuity mistake: When Fred is running from the oncoming white car, she runs toward a blue car getting fixed on the side of the road, but jumps out of the way as the white car hits the blue car. Fred hits the ground and rolls over to the fence, but in a following shot it shows Fred only just hitting the ground and she is on the grass, not next to the fence. (00:14:20)
Continuity mistake: When Angel and the others infect Connor with Cordy's blood, Gunn rips open Connor's shirt. In the following shots, the shirt closes and then opens again. (00:41:40)
Answer: Everybody including Angel saw her. After helping them and then being left alone to talk to Angel, Cordelia says that the Powers That Be let her come back one more time to help them. After Angel gets a call saying that she died, he realises that it was her spirit that was helping them the entire time.