If I am understanding this correctly, Masipa says OP is not guilty of Dolus Eventualis because he did not foresee that it was the deceased, e.g. Reeva (and not 'any person'), in the toilet. This is her view of the law. She will find him guilty of Culpable Homicide using the same criteria as Dolus Eventualis but applied to 'any person' and she has scope in sentencing to give as stiff a penalty as Dolus Eventualis.
However, OP wasn't charged with the murder of Reeva. He was charged with the murder of "a person, to wit, Reeva".