It did not appear speed was a factor, rather the driver did not see the woman.
He understood the car came to a stop on top of the woman and passersby 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.
It was a reminder to all drivers to take care around pedestrian crossings, especially in busy places such as malls.
A witness who works near the crossing said the woman was walking over the painted white lines when she was hit.
"I 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 elderly driver, and hoped she would get some support.
"There are so many near misses at that crossing.
"You just don't expect this to happen."
Tauranga Crossing centre manager Andrew Wadsworth 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 after a close call with a speeding driver.
He did not believe speed was a factor in this case.
Wadsworth said there had not been a lot of incidents at the crossing, but it was a carpark so sometimes things happened.