My theory is speculation, which people hear seem to hate, yet you love a new theory...!
And this one is sexual. I think the phone is the focus of all this and OP went upstairs after the killing to hide it. It's importance is underscored by the fact that although she is bleeding and he's chasing her (demanding it back), she's not giving it up.
She found something devastating there. Something that would destroy him. And since he is a narcissist, anything destroying him ends the world-- he's already a fading athlete and a crippled one at that. He is willing to throw over a friend just to not be the guy who shoots a gun into the restaurant floor. So we know it has to be worse than this.
Although she was hurt, she even makes sure she had it when she takes refuge in the bathroom. Why does she need it? To prove that her allegations she plans to make are true. She has threatened to expose him (as a pedophile? as a cross-dresser? as a gay man? As someone into bondage or horseplay or kinky in some other way.
When she discovers his, shall we say, irregularity, she mocks him. He is already taking performance enhancing herbs or whatever, so he has some insecurity in this area. And now she KNOWS that he needs the photos of shoes or the view of the anus of a donkey (we can't possibly know what his fetish might be).
He loses his cool and needs to prove to her that he is every bit 100% a man even if he does like *advertiser censored*. He begins to rough her up and she says no means no. So he rapes her, but in a twist of fate, he cannot get it up and she laughs. So he twists her arm, grabs an object and begins raping her with the object, pushing her against the bed, smacking her leg, and causing the bruising on the inside of her groin as he forces it into her vagina and her anus, causing the bruising in that area.
She is screaming which everyone heard as a fight since he is also yelling...she fights him off and runs to escape, grabbing her proof and hiding in the bathroom as his temper escalates. She plans to call for help but is holding the door closed.
She sees the gun and where it is aimed, otherwise, why would she cover her head with her right arm? She knew he was pointing a gun at her head.
He shot her in the hip down towards her groin to destroy the evidence of his sexual assault.
I don't think he planned this very far ahead, but it only takes a moment to form an intention to kill. He couldn't allow her to destroy the only thing he had left, his reputation as the South African golden boy.
In his mind, he was defending himself...and he still is.
Yesterday's continuous retching/crying was for the purpose of distracting the court's attention from the unspeakable crimes committed against Reeva. My theory of a sexual discovery, or perhaps a demand for a form of sex that was unacceptable to her, is backed up by the insistance that the open broadcast of the autopsy be squelched due to a respect for the dignity of the deceased suggests evidence of sexual depravity leaving its evidence on the body.
The court is not talking about protecting children from hearing about three bullet holes, one close to the vag, folks. They are wanting to protect the sensibilities of the family having to listen to medical notations such as torn vaginal canal, torn anus, semen in mouth, etc.
In my belief, the various bruises are indicative of a woman fending off a rape with an object, especially the strange bruise in the web of her fingers. Perhaps the handle of the cricket bat? A trophy?