The dozer was too close to the swing radius of the excavator and, when activating the steer clutch, went the wrong way.
The NSW Resources Regulator said dozer drivers should maintain a sufficient buffer between their machine and the swing radius of an operating excavator.
"Clear and specific procedures must be in place for when dozers are cleaning up within the swing radius," it said.
"Dozers should not try to work close to the edge of the swing radius and should at all times remain aware of the demarcation area."