Marion has had a long term relationship with Robin, but he has now left her for a younger woman, leaving Marion with excessive debts and two children under 7 years old. Marion sees him one evening with his new partner. They are going into a night-club together, and she sees Robin take out a wallet full of money. She becomes extremely agitated, and waits outside until they leave, some three hours later. She approaches the couple and asks Robin for some money, but he refuses to give her any. She picks up a broken bottle which is lying in the road, and stabs him in the chest. His girlfriend is so shocked that she suffers a fatal heart attack and dies immediately, but Robin is also able to stagger to a telephone box and call emergency services. He is so weak from lack of blood that he is unable to tell them where he is, the casualty unit is at full stretch due to a motorway accident and he is not seen for 40 minutes, by which time he has died from loss of blood.

(a) Excluding any defences available, discuss Marion's liability for:

        (1) The death of Robin.

        (2) The death of his girlfriend.

(b) What defence(s) could Marion raise to reduce her liability for the deaths of Robin and his girlfriend?