Murder (via DE) and Culpable homicide should not really be rolled together on a sliding scale. I think this is causing confusion.
They are completely different charges.
PPD is a defence to murder.
However if in the context of your PPD defence, you killed another person through negligence - then that is a classic manslaughter (CH) type of case.
Essentially Masipa found OP guilty of CH because his behaviour fell short of what we objectively expect from a reasonable person.
His conduct in killing Reeva was "outrageous" and not a reasonable mistake. This is what makes him "culpable" for her death
They are completely different charges.
PPD is a defence to murder.
However if in the context of your PPD defence, you killed another person through negligence - then that is a classic manslaughter (CH) type of case.
Essentially Masipa found OP guilty of CH because his behaviour fell short of what we objectively expect from a reasonable person.
His conduct in killing Reeva was "outrageous" and not a reasonable mistake. This is what makes him "culpable" for her death