I think that Pistorius has got a fairly large safety net of knowing that there is no real way of proving any part of what was in his mind that evening.
We can have serious doubts that Reeva didn't say a single word to him as he was getting the fans in from the balcony. We can have doubts that he couldn't see anything at all in the room (bearing in mind that he'd just woken up, so his eyes would have adjusted to the light). However, I'm not convinced that we can say that from those doubts, we can leap to; there must have been an argument, and he must have followed her to the toilet.
An awful lot hinges on the testimony of the witnesses around. All of the ones we've seen so far are convinced they heard an argument, and all are convinced they heard a woman scream. If these witness statements are correct, then he did know it was her. What the defence are saying is that these are not reliable statements, and that what they heard wasn't Reeva shouting and then gunshots, but Oscar shouting, then the cricket bat.
I have doubts about these witnesses too, based on the De Menezes case in the UK. So many witnesses came forward to say that they saw a things that were simply not present. ( news.bbc.co.uk/1/hi/uk/4177082.stm ) Witness memories are so very complicated, and even when you're being truthful, it's very hard to say what you know for sure, and what your head puts there because of circumstances.
The one witness I think is pretty reliable, is the one whose son had an exam the next day. She woke because of an argument - not because of bangs, and she had reason to time check because her son needed to sleep. She grew more annoyed the longer the argument went on. She had reasons for remembering what she did outside of later hearing what had happened.
I am interested to see whether the defence brings forward some closer witnesses who say 'no, didn't hear a thing until the gunshots, and then I heard a man calling for help, and I knew it was 3 in the morning because I'd stayed up all night to watch a very quiet football match.'
So I'm still wedged on the fence with the Murder knowing it was Reeva.
I remain firmly convinced that he is guilty of Murder Dolus - Eventualis (he intended to kill whomever was behind that door, and even if that wasn't his intention he knew that would be the result, and culpable homicide - he did not sufficiently check for Reeva in the bedroom before he shot.