The Full Court in Victoria distinguished between the two classes of homicide of murder by reckless indifference and manslaughter by criminal negligence in R v Nydam, in which malice aforethought was definitively ruled out as an element in a charge of manslaughter by criminal negligence.
How out-of-network care is handled is the biggest difference between an HMO and PPO, but over time, that difference is blurring as more HMOs allow for some out-of-network benefits, and more PPOs decrease how much they'll pay for out-of-network visits.
If you get your health care from these preferred providers, you pay less. PPOs are a type of managed care health insurance plan like their distant cousins, HMOs. All managed care health plans have rules about how you must get your health care.