I didn't say that you misinterpreted the law. I don't think an informal study of law over several laws means that anyone can state emphatically that they know what the law of another country is without any caveat. I said I don't agree with your interpretation that the judge cannot render a CH verdict.
No, you didn't clarify that's what you disagreed with and had I actually said that, I would disagree with myself.
Here's a recap that hopefully clarifies:
The judge will only consider culpable homicide as a charge IF Oscar is acquitted of the murder charge. It isn't 'either/or'. She first has to determine there was not intent to kill Reeva; there was either no intent to kill an intruder or, if there was, that Oscar's defence has 'absolved' him of intent (meaning proving putative private defence); and lastly, that he couldn't have foreseen the consequences of his actions and in order to determine whether he could reasonably foresee those consequences the reasonable person test would be implemented.
If Oscar is acquitted of murder because intent has not been proven, then they move on to considering culpable homicide. A determination of guilt or innocence for culpable homicide is also reached by implementing the reasonable person test. That test of course is a mixture of subjective factors relevant to a theoretical reasonable person weighed against objective factors relevant to the crime itself (like choice of ammunition). The more objective factors, the law reasons, the more the defendant should have been able to foresee the consequences of his actions and the less likely it is he could be considered to have acted 'reasonably'.
The top charge must be both considered and rejected before contemplating lesser offences, such as culpable homicide. If he is convicted of murder, the culpable homicide charge becomes moot.
ETA: The post I initially responded to seemed to imply that the only possibilities were premeditated murder or culpable homicide. Apologies though, if I'm misinterpreting. You do know, I'm sure, that the State doesn't have to prove premeditation at all in order to secure a murder conviction. The only proof required is establishing intent. The two are very different principles in South African law. Here is the legal definition for intent, also referred to as specific intent:
http://legal-dictionary.thefreedictionary.com/Specific+Intent