This isn't the trial though. We shouldn't know what the witnesses have said yet. We know OPs version of events without any cross examination. The police version of events sounded highly plausible to me until the defence lawyer started picking it to bits. The prosecution haven't had chance to do likewise to Pistorius. So it's easy to take what he says as "fact" so far.
A lot more will come out at the trial.
I do agree with the prosecution that he doesn't seem to have grasped the severity of what he's done. The statement from his agent a couple of days ago when he said they'd discussed his race schedule astounded me.
People do react in different ways, though. How many times just on DS have people in news stories been declared innocent or guilty because of tears or lack of. Hairdo's and outfits have been examined in detail before coming down on one side or the other - often erroneously
Perhaps focusing on something that is second nature to him, like his running, is a way of keeping himself together. Perhaps it was just his agent trying to put a spin on things, which wouldn't be unknown either. Whatever the outcome, whatever the reasons, whatever he meant to do, he has taken someones life - and that can't be easy to deal whoever you thought it was or wasn't.