The injuries mentioned in the judgement are certainly inaccurate, but I'm not sure their accuracy would have had a huge impact on her decision. Ignoring Saayman certainly would, of course.
I've said on here before ... I think the level of debate between members on here and the collective time spent by members on this case, gives us a much more detailed analysis than Masipa and 2 assessors could hope to have. I honestly think a lot of subtle points made by Nell were just completely missed by the court. What was on the surface, a simple case, became increasingly complex and tangled. Masipa's hearing also concerned me, when she asked OP to speak up so she could hear him. I wonder what else did she not hear during the proceedings?
As far as ignoring evidence is concerned, I guess she would have to dismiss some evidence no matter what her conclusion. There didn't appear to be a judgement which could take into account all the evidence and still fit. I believe, rightly or wrongly, she went with her gut reaction and then tried to assess how much evidence supported this view. Anything that didn't, she had to find an excuse for it's exclusion. It would have been the same process if she had decided he was guilty of murder and it would be an interesting exercise to see which pieces of evidence she would have to dismiss for this conclusion. I'm struggling to think of any apart from OPs own testimony. I think that tells us something !
Thinking on Masipas preceived bias ... Before the shooting, OP was seen as a national hero. He was seen as a kind of figurehead for SA, a global representative for their people. Trying their national sporting hero on a global public stage must have brought a lot of subconscious bias to the process. Many in SA would feel finding OP guilty of murder would be damaging to SA itself. A loss of an important person for them on the global stage. Perhaps this was part of Masipas subconcious bias. You can still see a lot of OP supporters clinging to the wreckage and refusing to believe he did anything wrong. They still want to believe that he is their hero, someone they looked up to, were inspired by and they can't face losing this.
When one has strong core beliefs (in this case strong beliefs in OP as a good person), it is natural to look for reasons to support or even strenghten those beliefs. Most people do not look for reasons to destroy those core beliefs, especially if they have invested a lot of emotion during their lives in supporting those core beliefs.
All just my opinion ... for what it's worth.