The inspectorate is undertaking a formal investigation on how experienced bulldozer operator, Allan Houston, 49, lost his life in the incident.
The bulldozer was traversing - with the blade not in contact with the ground - along a bench in an area where three bulldozers were pushing overburden material.
"The bulldozer operated by the deceased, for a reason yet to be determined, went over the bench's crest and rolled downwards approximately 20m," the inspectorate said.
"The bulldozer came to rest on its roof in an area of mud and water approximately 2m deep."
According to the inspectorate, another bulldozer operator who witnessed the incident "called in" the emergency immediately and an emergency response team attended at the site.
"Queensland Police Service attended at the mine and handed over control of the scene to the Queensland Mines Inspectorate," it said.