Interesting. He certainly accepted that if he fired a warning shot in the bathroom that he could have killed himself. My problem is with the judge and how she interpreted his many discrepancies about whether he accidentally fired, whether he fired low so as not to kill somebody, whether his gun fired without him thinking about it, ie not consciously thinking of the outcome. As far as I am concerned he knew exactly what he was doing. The problem for me are his many explanations of why he fired and how the judge determined that it was CH rather than DE. Was all the confusion about what really happened enough to sway the judge?
I think you will need to carefully watch the relevant testimony again. Nel asked him if he every thought of firing into the shower and he said that he might have been injured. He did not say that was the reason he did not fire into the shower at the time nor did he think that at the time. He went on to make this clear in response to Nel's further questions.
If Nel had really wanted to know if he thought it at the time he should have asked him if he "thought it at the time". But that of course was not his first intention.
I am intrigued by your statement that OP had "many explanations" for why he fired. OP was consistent in that he fired because he heard something he thought was an intruder attacking and before he knew it had fired 4 shots. What were the other of his "many explanations"?