It's still not cut and dried at all though.
There is only one person, Estelle Van De Merwe, who heard any talking before Reeva was shot. She is the only one who can suggest an argument took place.
Her testimony isn't what you could really call 'watertight'
'I heard people talking in loud voices, as if they were arguing'.
'I could not hear what language they were speaking'
After tests were done in OP's bedroom of a man and woman screaming as loud as they can, Esteele Van De Merwe said 'I could not hear anything'.
There are four witnesses in addition to Van der Merwe. All were 100% adamant they heard a woman's voice at approximately the hour OP shot and killed Reeva.
It's very clear.
Even with no witnesses, OP's own affidavit describes premeditated murder. Five witnesses hearing a woman's voice followed by gunshots confirms what happened. The defense that OP replicated the very sounds of the murder is a unique defense, but not even close to reasonable. What's next? The hologram defense where a defendant claims he produced a holographic image of the exact crime which is what all the eye-witnesses saw?
If it wasn't so tragic it would be laughable.