Sam Casella, the sole director of Quattro Constructions Pty Ltd, was convicted and fined $120,000 after pleading guilty in the District Court to failing to comply with his health and safety duty, exposing a worker to serious injury or death.

Quattro was subcontracted to install formwork by a concreting company that was itself subcontracted by the principal contractor, Combeda Constructions, on a residential and commercial complex job.

On January 27, 2021 a SafeWork inspector visited the site and sent multiple improvement notices to Combeda.

The inspector observed that there were no adequate systems to prevent someone from falling; there was no handover certification for internal scaffolding in the lift shafts; and Combeda had not ensured work above two metres was carried out safely.

On the morning of February 1, Quattro's site supervisor Anh Dang gave instructions to Samuel Tembeleski for work on level two, which was to be carried out next to a void designed for electrical, water and air-conditioning.

The hole was covered by a piece of plywood but there was no signage or markings to alert workers.

When Mr Tembeleski, then 19 and a third-year apprentice, stepped onto the plywood it gave way, causing him to plunge about 12 metres to the basement floor.

He suffered multiple pelvic, lumbar and limb fractures, dislocations, a tear to the aorta, injuries to his lungs and internal bleeding, requiring surgery and a stay in hospital of over three weeks.

In the days prior Mr Dang had instructed other workers to strip the formwork below where Mr Tembeleski fell, but did not inform Mr Tembeleski.

Despite his position, the court heard Mr Casella had no involvement in running Quattro, which was one of a group of companies operated by his cousin Peter Milazzo.

At the time, Mr Casella was working as a truck driver or yard manager for another of his cousin's companies, and he did not explain to the court how he came to be appointed Quattro's sole director and secretary.

But Judge Andrew Scotting noted that Mr Casella admitted his failures were "extensive".

Mr Casella did not inform himself of risks and hazards at the site, did not require a safe work method statement for Quattro, and did not have appropriate risk assessments undertaken.

Mr Tembeleski and other workers did sign another safe work method statement for another of Mr Milazzo's companies but it did not provide guidance on securing plywood covers nor require warning signs for such holes.

Another employee gave evidence he was instructed to back-date this document.

"The risk was obvious and well known, both to the offender and in the industry. There was ample guidance material available to inform the offender of the risk and the control measures that he should have facilitated for Quattro to take," Judge Scotting said.

He said there had been a deliberate attempt to avoid health and safety duties.

Mr Tembeleski was vulnerable because of his inexperience, Judge Scotting said, and had been lucky to survive the fall.

He said Mr Casella expressed sorrow for the incident but lacked insight, describing him as having been "used as a stooge".

He said others "may also have engaged in culpable conduct" in relation to the incident.