Yonic screwdriver, the doctor said that it was unintentional, he was very clear that he believed it was an accident and from Pistorius' reaction he believed that he had not intended to kill her, and the judge accepted this entirely.
But it doesn't really matter, if it had been the other way round and he had said 'I don't believe his remorse was genuine, I think he meant to kill her' and the judge used that to acquit him it would still be completely unreliable as a piece of evidence.
It's utterly subjective, it's not evidence. It's an opinion. Nobody can say with any certainty whether the emotions displayed by another human are genuine or feigned. You just can't do it, nobody can unequivocally declare one way or another. So the judge just shouldn't have relied on that evidence, it was subjective and unreliable.
And when she dismissed witness testimony as inherently unreliable in the prosecutions case but accepted it without quibble from the defence she directly contradicted herself.