I don't understand this. An illegal lane change, someone is killed, and the result is not even a ticket? Does that make sense? Fiddling with the heater or the radio causes you to be a menace and that is acceptable? What if it was a cell phone (which it probably was) or just plain inattentiveness? Are those things OK too? What if she intentionally cut off the van but claimed it was innocent? Or maybe she is just a bad driver. How can the police know for sure? Isn't the result the same? She managed to sweet talk her way out of any responsibility? Or maybe she is connected in some way?
I have always believed that if you want to kill someone and get away with it, do it with your car. The only thing you have to be careful to not do: 1) be under the influence of alcohol or illegal drugs or 2) leave the scene. #1 is more critical than #2, because you can claim you thought you hit a deer or road hazard, and may be able to walk away with only a slap on the wrist (if that).