Instructor sentenced to jail over participant's death

[Article - https://www.channelnewsasia.com/singapore/safra-instructor-acsi-student-rope-obstacle-course-death-4047391?fbclid=IwAR0bNq9JC7WZyxSFB_Rx0plDbFxyhQCL3TSFZVTS3vndE8ymY4EYAIryrcA]

I can understand if this article is not written by someone with more intimate knowledge of the profession, but some parts of the article got me wondering:

1. Is there any significance to describing the instructor as a 'volunteer'? What difference does it make?
2. The instructor was charged with causing "grievous hurt to Jethro through a rash act by illegally omitting..." Are safety procedures also 'laws'? I'm not a legal expert, but does this mean that if practitioners, in the course of their duties, overlook a procedure (let's assume it doesn't result in serious consequences), they are in fact breaking a law? Or is it that the nature of the consequence determines if the act (of overlooking a procedure) is unlawful?
3. "According to the prosecution, a participant who had worn the harness properly would have been able to climb back onto the obstacle more easily as the person would have been in a higher position." Particularly with the use of daisy chain straps, this highlights the importance of attaching it to a participant such that there is not too much slack. I have seen many cases where, due to time or participant pressures or maybe even due to poor training, instructors just use the full length of the daisy chain rather than assess the individual participants' heights and attach accordingly.
4. There were two other instructors stationed at the towers in between the obstacles. If the instructors are required to observe participants negotiating the obstacles, then they should have noticed that Jethro was not properly harnessed and either a) asked Jethro to turn back to the despatch point so that his harness can be adjusted properly or b) when Jethro arrived at the first tower, the instructor there could help adjust his harness.
5. While Hakim's lawyer said that "he had exercised a poor split-second judgment call", the other possible area of poor judgement is the time that elapsed from when he fell off to being lowered to the ground from the obstacle, which was about 30 minutes. Typically, in high ropes rescue scenarios that require lowering a participant to the ground, the whole procedure should take between 3-5 minutes. It appears that the decision to lower Jethro took too long and came too late.