(a) When committed by accident and misfortune in doing any lawful act by lawful means, with usual and ordinary caution, and without any unlawful intent;
(b) When committed by accident and misfortune, in the heat of passion, upon any sudden and sufficient provocation;
(c) When committed upon any sudden combat, without undue advantage being taken, and without any dangerous weapon being used, and not done in a cruel or unusual manner.