One witness heard arguing and shouting about 2am. Reeva eats something a couple of hours before she's killed. Give or take an hour or two, she was eating somewhere between midnight and 1am when they were both allegedly asleep. This suggests that probably neither of them were both asleep at the same time, unless they both slept at 10pm, then Reeva woke up, felt peckish and went to get something to eat (this didn't wake up OP funnily enough) and I doubt she kept a meal of vegetables in her overnight bag.
So she gets up to get some food and comes back to bed.
If OP is asleep, does she check his phone and find out he's been watching violent




on Valentine's Day? Does he wake up and go nuts about her checking the phone? The argument starts about 2am (fitting in approx. with her last meal) and ends with OP hitting her or going at her with a bat? Could be when she started screaming.
She grabs her phone and flees to the toilet for safety. He then goes to the balcony to bring in the fan(s), closes the blinds and doors (making sure everything's in darkness), and then heads to the toilet with his gun to terrorise her. Maybe he even tells her if she doesn't come out, he's going to shoot. She doesn't come out and he shoots anyway and kills her.
She hasn't been able to make a call on her phone (that we know of) and we don't know how much of the crime scene OP altered regarding the phones. He certainly had plenty of time to move things about. But if she was locked in the toilet with an angry OP on the rampage, she would surely have tried to call someone if she'd had her phone on her.
I'm just rambling here and trying to get an idea of the timeline, last meal she had, and the argument that allegedly started around 2am. I don't rule out premeditation because I think he knew exactly what he was going to do once she'd trapped herself in the toilet and wouldn't come out. Just my feelings on it at this moment in time.