An investigation by the regulator found that on November 15 2019 at 6.24am, the worker attended the Glencore owned mine and started his shift after being on a roster break for several days.
At 9.43am, the worker drove a rubber-tyred dozer into a working strip area of the mine, lowered the blade and parked up.
A short time later, another mine worker attempted to make radio contact with the dozer operator and had no reply.
The mine worker followed up, making a request to mine dispatch to contact the dozer operator.
At 10.15am, a nearby haul truck driver approached the dozer and saw that the worker was slumped over the steering wheel.
The truck driver found the worker unresponsive and unconscious.
Emergency response was activated. Mine workers and ambulance workers attempted to revive the worker however they were unsuccessful.
After investigating the circumstances of the worker's death and examining information provided by the Coroner, the regulator concluded the worker's death was not considered work-related.
"Mine operators should have effective health monitoring programs in place to ensure workers are healthy and fit to work at a mine," the regulator said.
"Regular medical examinations should be undertaken by qualified medical practitioners."