A waste truck company has been spared some convictions over its workplace failures that led to a fatal crash on South Australia's South-Eastern Freeway.
In August 2014, Darren Hicks was driving a truck for Cleanaway Operations when it suffered a "catastrophic brake failure" and reached speeds of up to 150kph.
Thomas Spiess, 57, and Jacqueline Byrne, 41, were killed when the truck smashed into their cars at the bottom of the freeway.
Mr Hicks and another motorist were seriously injured.
Charges initially laid against Mr Hicks were dropped in 2018.
But his employer was last year found guilty in the Adelaide Magistrates Court of eight counts of failing to comply with its health and safety duty on the basis it had failed to adequately train and supervise the driver and maintain a safe system of work.
Mr Hicks, who is now a Paralympic gold medallist, had obtained his heavy vehicle licence two months before the accident and had worked for the company for just days.
Eight years after the fatal crash, Cleanaway Operations appealed its conviction in the Supreme Court on multiple grounds, arguing Magistrate Simon Smart had erred in finding that there was sufficient evidence to prove it was reasonably practicable to assess the competence of Mr Hicks to drive down the freeway.
Chief Justice Chris Kourakis dismissed the company's appeal, saying Cleanaway had breached its duties.
"The risks of a collision between a heavy vehicle like the vacuum truck and other road users arising from a failure to control its speed on the steep descent along the freeway into a busy suburban intersection was obvious and unusual," he said.
"Driver competence in effecting appropriate gear changes was an important safeguard against that risk.
"There was no practical reason for not assessing Mr Hicks's competence in gear selection for a descent of the freeway before he was directed to drive the vacuum truck down the freeway."
In his written judgement, Chief Justice Kourakis said while Cleanaway Operations had a system in place to assess drivers, it was not regularly used.
"It was not effectively implemented in a timely manner before Mr Hicks set off in a heavy vehicle with a manual gear box on a descent which had particularly high risks and which required a well-trained or experienced driver," he said.
"The brake failure was both a circumstance against which competence in the use of gears was a safeguard, and a problem which was exacerbated by Mr Hicks's failure to use the gears effectively.
"It is a notorious fact that the causes of industrial and other accidents are often multi-factorial; it is also a precept of workplace safety that, for that reason, multiple safeguards are necessary."
But Chief Justice Kourakis did set aside six of the company's eight convictions, saying each measure the company had failed to implement to eliminate or minimise the risk should not be a separate offence.
"The driving of the vacuum truck down the freeway is one course of conduct," Chief Justice Kourakis.
"The risk could have been minimised by any single one, or any combination, of the reasonably practicable measures alleged: providing a supervisor, not allowing Mr Hicks to drive, properly training Mr Hicks on manual gearboxes, or properly training Mr Hicks on driving down the freeway.
"However … there was a single breach of the duty owed to employees and a single breach of the duty owed to other persons."
The company's convictions for six of the counts will now be set aside.
The court is yet to impose a penalty for Cleanaway Operations.
