"If in the course of an affray a person uses unlawful violence amounting to an assault and that assault is the only act that all sober and reasonable people would inevitably recognise must subject the victim to the risk of some harm resulting therefrom, and if the victim dies as a result of the affray but not as a result of the assault, is anyone who is guilty of the affray also guilty of manslaughter, whether or not he was party to the assault?"