The full report:
What stood out for me is this:
I am of the view that there is an argument that Mr Bobb was negligent in his driving. However, having regard to all the evidence before me and noting in particular the conflicting evidence in relation to Mr Hall’s conspicuity for other drivers, the loss of evidence crucial to determining the conspicuity of Mr Hall’s clothing and accoutrements, the physical environment of the road at the relevant location, and the high standard of negligence required by section 29, I do not have reasonable grounds for believing that Mr Bobb has committed an indictable offence.
Basically, the law requires physical evidence of a driver being negligent to a high standard ... killing someone isn't enough to prove you're driving in a negligent manner. Even though the coroner thought the driver was negligent in his driving it wasn't enough to find so in her report due to the legal requirements.