How have courts distinguished criminal negligence from implied malice in the context of involuntary manslaughter?

In People v. Butler (2010) 187 Cal.App.4th 998, 1008, the court distinguished criminal negligence in the context of involuntary manslaughter from implied malice in the context of murder:

(See also People v. Cleaves (1991) 229 Cal.App.3d 367, 378 ["[I]f the defendant commits an act which endangers human life without realizing the risk involved, he is guilty of [involuntary] manslaughter, whereas if he realized the risk and acted in total disregard of the danger, he is guilty of murder based on implied malice."].)