A paramedic who was killed during a cliff rescue on the NSW south coast was inadvertently dragged off a cliff ledge by a rescue helicopter that was meant to winch him and his patient to safety, a report into the accident has found.

Light was fading quickly at Carrington Falls, near Wollongong, on Christmas Eve in 2011 as special rescue paramedic Michael Wilson attempted to rescue an injured canyoner from a waterfall known as Bridal Veil Falls.

Mr Wilson, 42, had abseiled down to the injured canyoner, who had set off an emergency personal locator beacon earlier that afternoon after falling from the top of the cliff.

Mr Wilson had planned for his patient and himself to be winched into the helicopter as it hovered near the cliff ledge, about 15 metres from the base of the waterfall.