The operator of the dump truck parked up on a dump to allow a hot seat changeover.
Problems arose when the operator was unable to activate the primary access ladder to exit the truck.
After several attempts, the operator restarted the truck, exited via the emergency ladder and then activated the ground level e-stop and isolation switch.
The truck then rolled forward approximately 50m, contacted a windrow and rolled back about 17m before stopping.
The NSW Resources Regulator said the truck was not parked in a fundamentally stable manner.
"Changeover between operators should take place at designated park up areas where possible," it said.
"When this cannot occur, operators should put equivalent controls in place to manage the risk of vehicles rolling away, including fundamentally stable parking."
