What is the test for a claim that a homicide was committed through misfortune or by accident?

"Generally, the claim that a homicide was committed through misfortune or by accident 'amounts to a claim that the defendant acted without forming the mental state necessary to make his or her actions a crime.' " (People v. Jennings (2010) 50 Cal.4th 616, 674, italics added (Jennings).)¹¹ "[I]f A, in the heat of passion and with sufficient provocation, strikes B with his fist after a sudden quarrel, with no intent to kill or injure B, and B dies as a result of the blow, the homicide is excusable under Penal Code section 195." (People v. Mayes (1968) 262 Cal.App.2d 195, 197, italics added.)