The EWP was being driven toward the ramps of a low loader when it slipped off the edge of the deck.
The operator was in the EWP's basket at the time.
A spotter was helping guide the operator during the unloading process.
The NSW Resources Regulator said mine operators had to have controls in place to manage the risk of EWP's overturning during loading and unloading activities.
"EWPs should be matched appropriately to the size of the transport vehicle - length and width - and be centrally positioned on the deck or tray," it said.
"Operators should plan loading and unloading tasks and final machine position before commencing the task."