A man died after he slipped on his own vomit while getting out of a grader and fell under its back wheels.
Coroner David Crerar has found Garry Willem Voorkamp, 54, a machine operator from Lorneville, Invercargill, died on September 24, 2014 from a massive head trauma.
He became ill while operating a grader for South Roads in the Lumsden area and vomited.
While the grader was still moving he got out of the driver's seat and moved to the open left-handed side of the door of the cab.
"It then appears as if Garry Voorkamp has slipped in his own vomit and has fallen from the grader.
"The machine was by then out of control and it ran over his head, causing fatal injuries," Mr Crerar says.
Mr Voorkamp was experienced and a qualified foreman.
His wife Katherine Voorkamp said her husband may have declined an offer to go home because he did not want to put anyone out or let the foreman of the day, a friend, down.
He had been unwell that morning with an eye irritation and took one tablet of Naprosyn, an anti-inflammatory used for pain relief that would have had limited impact on an eye infection.
Mr Crerar could not find that Naprosyn had caused the vomiting.
Shortly before he vomited Mr Voorkamp steered the grader across the road, which was unusual, but he waved at witnesses and was presumed to be alert.
He appeared to have vomited to the open grader door then attempted to get out of the cab.
"Why he did this while the grader was still moving cannot be established," the coroner said.
He has suggested South Roads put non-slip flooring the the cabs of its graders.
The company has said it has strengthened its protocols for how it treats employees who become unwell whilst still at work.