BBM - then why not just say "Yes, I killed her". It's just one more thing that he doesn't want to verbally admit. He also said he'd 'taken responsibility' but I don't have a clue what he meant by that. Taken responsibility for what exactly? Killing Reeva? He could hardly deny it and there's no one else for him to blame for once, so what do you think he meant when he said "I've taken responsibility"?
Well, Nel said he hadn't taken responsibility for the killing and OP contends he has. Pretty straight forward.