Rob, convinced of his wife Pauline's infidelity, decides to kill three of her supposed lovers, Xavier, Yusuf and Zane. Rob persuades Xavier to take a train to London because he has hired Hitman, a professional assassin, to kill Xavier on arrival. Due to a landslip, the train crashes en route, killing several passengers, Xavier among them. Meanwhile, Hitman is having troubles of his own. His presence at the railway station has attracted the attention of the police to whom he is well known. Two officers approach him. He strikes one, Adam, knocking him onto the railway line and stunning him. Hitman then runs to a nearby car, pulls the driver (Chris) out and, in order to effect his escape, drives the car deliberately at and over the second officer, Brian. Adam dies from injuries sustained by being struck by a train and Brian dies one week later in hospital having refused a blood transfusion. Chris fares little better; he suffers a heart attack from the shock of being wrenched from the car. He is rushed to hospital where, in error, he is wheeled into an operating theatre and his appendix is removed. He dies from an infection arising from the operation. Rob administers poison to Yusuf, believing and intending the dose to be fatal. In fact the dosage is insufficient. Pauline has her own reasons for wishing Yusuf dead and, acting independently and in ignorance of Rob's activities, subsequently administers a similar dose, and, cumulatively, the poison kills Yusuf. Rob hires a witch to put a curse on Zane's new car which mysteriously suffers a complete brake failure when Zane is driving, not killing nor even injuring Zane but knocking Quentin, a passing pedestrian, down. Quentin dies from his injuries.

Discuss the problems of causation which arise.

FOr this question, what cases and theories would be relevant to point out? and how could I sturcture it?