"The noise of the crash woke us and I thought somebody had gone into the [road-side] barrier so I just grabbed my torch," Mrs Judson said last night.
"I looked in the car with my torch and there was nobody in there - I yelled into the car, calling out, 'Is anybody there?'"
A neighbour who had arrived just before her, retired trucking operator Peter Morris, was meanwhile straining his eyes looking for the driver from the seawall metres from the car.
"I shone my torch at Peter and he said, 'He [the driver] is right here at my feet'," said Mrs Judson.
Mr Morris, who like his neighbours was in his dressing gown, told the Weekend Herald it was difficult to make out anything in the dark before he noticed the driver right under his nose. "He was splayed out - spread-eagled," Mr Morris said.
Dr Judson, who was made a member of the New Zealand Order of Merit after retiring in 2012, said he feared the driver was dead because he could not feel a pulse.
But then he noticed shallow breathing, checked that the man's airway was clear and - after noticing blood around his mouth - decided it was safest to leave him where he was until an ambulance arrived.
Mr Morris suspected the man had managed to crawl out of his car, rather than being thrown out, before collapsing above the shore.
Although an airbag went off inside the car, he expected it would have protected the driver only from the first impact rather than several others which followed. He said the impact of the car crashing through the trees shook his home.
Mr Morris said speeding was a problem for residents at the bottom of Curran St but he felt his protests to authorities had fallen on deaf ears.
People drove down the bridge connector "at a rate of knots".
Other neighbours woke to find fallen trees blocking the shared pedestrian and cycling path along Curran St leading to Westhaven, and a tangled mess of iron railings formerly protecting a set of steps down to the beach, now taped off.
The police serious crash unit are investigating the incident.
A spokeswoman said blood samples were taken from the driver as a matter of course, but she had no other details.