The candle drop...
Did Annie knock the candle down on purpose or on accident?
I say on purpose (obviously pretending it was on accident).
Even though she was a psycho, she was very smart... that's why she was able to hide her previous crimes.
Great point, and it adds an extra layer of creepiness to the film.
Throughout the movie, there are moments that make you wonder whether she caused certain events or not. For instance, take his legs when we first see them. Were the injuries a result of the crash, or did she deliberately inflict them? It's up to our imagination.