The helicopter had to wait for cloud to clear and arrived about an hour after it was first called at 12.30am.
"We hovered for 45 minutes and illuminated the scene so they could actually put her on the winch stretcher safely, while they were working in what I would say were precarious positions."
The woman was airlifted to Waikato Hospital with a suspected broken pelvis and femur, along with back and internal injuries.
Mr Ford said the winch rescue operation was over in less than an hour-and-a-half, while it would have taken a number of hours to carry the woman down through very steep terrain.
"She's tumbled down that hill, so you imagine carrying someone down on a stretcher," he said.
The group of abseilers had earlier walked up Castle Rock, a prominent feature in the area, to abseil down its buttresses.
"It looks like it would be good for abseiling because access is reasonably good - you don't have to climb your way up, you can actually walk up through a steep access and abseil down."
Mr Ford said the helicopter crew had spotted the group on the rock earlier in the day while flying past on another job.
"We actually circled and thought, 'That's pretty cool, how do we get up there?'
"We were actually looking at maybe doing it ourselves sometime, so the ironic thing is, about five hours later we're coming back to winch someone off the same place we want to have a walk up."
Mr Ford said it was fortunate they had flown past the rock earlier because the crew knew exactly where it was.
He praised everyone involved in the rescue for their teamwork and communication.
The rescue helicopter, one of two Auckland-based Westpac rescue aircraft, has been stationed in Whitianga over the summer holidays due to the popularity of Coromandel holiday spots.
