Following an argument in the street, Alastair punches Hashim who falls over, cutting his elbow. Alastair walks away. As Hashim is attempting to get up he bumps into Isobel who has just turned the corner. Hashim falls over again, hits his head and loses consciousness. Isobel, who is in a hurry, keeps on walking after the collision and does not look behind her. Hashim is taken to hospital suffering from concussion and loss of blood. He is given a blood transfusion and he regains consciousness. However, the blood transfused was infected by a life-threatening virus, from which Hashim dies three weeks later.

Discuss.