Smith was shopping at Tauranga Crossing with his daughter and the pair were walking out of the travel agency helloworld, when he heard a "brief shriek".
He looked to his left and saw the car hit the woman.
"She went up on to the bonnet and her bag flailed up with her," he said.
Smith said the woman rolled down the bonnet and underneath the car's front wheels.
"As soon as I saw her roll underneath [the car] I had to turn my head and close my eyes."
He turned around again to see the car come to a stop with the woman in between the car's front and rear wheels.
He then turned around to hand his shopping bags to his daughter so he could go help move the car.
At this point, multiple other people had stopped to help the pedestrian.
"She was breathing but she was in very poor shape," he said.
A witness who works near the crossing said she saw a woman lying "face down and motionless" on the road.
Nearby businesses gave those providing first aid towels and other items. An intensive care nurse was among those who helped before the ambulance arrived.
She said she also felt very sorry for the driver and hoped they would get some support.
"There are so many near-misses at that crossing.
"You just don't expect this to happen."
Western Bay acting Senior Sergeant for road policing Wayne Hunter said inquiries were ongoing and no charges had been laid.
Hunter said a woman had been walking over the crossing when she was hit by a car.
It did not appear speed was a factor, rather the driver did not see the woman, he said.
He understood the car came to a stop on top of the woman and passers-by helped move it off. There were conflicting reports, at this stage, about exactly how that happened but he understood they had not lifted the car.
An off-duty GP and paramedic were among the shoppers who rushed to help until the ambulance arrived.
The injured woman was in a serious condition in Tauranga Hospital, he said.
On Saturday, Tauranga Crossing centre manager Andrew Wadsworth said the mall would do everything it could to help police.
It had already provided security camera footage of the area but he understood the incident had not been directly captured.
He was very concerned to hear the injured woman was in a critical condition when taken to hospital and hoped she would recover.
"Our thoughts are with her and her family."
He said the centre had recently put speed humps around its pedestrian crossings.
Wadsworth said there had not been a lot of incidents at the crossing.
Tauranga Hospital has been approached for an update on the woman's condition.
