Jean Harrison's elusive killer may not have seen her crossing the street but they couldn't have missed the Sydney grandmother hitting their bonnet in the fatal collision, an inquest has heard.
The elderly woman was struck and killed two days after her 83rd birthday while walking the 800-metre trip from a shopping centre to her home in residential Miller on February 17, 2015.
Despite a lengthy police investigation and a $350,000 reward for information, her hit-and-run death remains unsolved, her inquest heard on Tuesday.
An anonymous tip initially pointed detectives to a trio of trail bike riders but police and road safety researcher Raphael Grzebieta now believe a car was most likely involved.
It was possible the driver coming out of the Dorset Place cul-de-sac didn't see Mrs Harrison crossing due to her being hidden in the car's A-pillar blind spot, the professor said on Tuesday.
"But so far as thereafter?" NSW coroner Elizabeth Ryan asked.
"Oh, yes, you'd feel it," Professor Grzebieta said. "You'd have seen Mrs Harrison coming on to the vehicle bonnet."
Mrs Harrison had earlier been heading home from the shops in a taxi with neighbours but she got out halfway after realising she'd left her purse behind,
CCTV captured her leaving the shopping centre again at 11.37am - eight minutes before she was found unconscious at the entry to Dorset Place, her inquest heard on Tuesday.
The driver would "definitely" be aware of the impact as "something would have thudded", Prof Grzebieta said.
Investigators were working with little forensic evidence, the inquest was told.
No scuff marks, broken glass or fallen objects had been found on the road to indicate the point of impact, while only ambiguous tyre marks were found on the nature strip.
No person had come forward to identify the vehicle involved either.
Assuming the grandmother was taking a normal route across Dorset Place on her way home, Prof Grzebieta calculated Mrs Harrison was hit seven metres from where she was found by a vehicle travelling about 30 to 40km/h.
Without any marks on the woman's clothing, he said the only way a motorcycle could be involved was if it was a touring bike, like a Harley Davidson.
A forensic pathologist had also ruled out a simple fall, given Mrs Harrison had rib fractures, head trauma and a fractured pelvis.
In his opening address on Tuesday, crown advocate Stephen Kelly said police had identified a man who'd driven a stolen Subaru Forester on February 17.
"(But) the police investigation has not been able to directly link this vehicle or any other vehicle to Mrs Harrison's death," he said.
Noting a lot of information given to police had come from "unreliable sources", Sergeant Kelly said the male person-of interest had offered a fake name and pointed detectives towards the trail bike riders when speaking to police shortly after the crash.
In an interview on November 4 this year, the man - whose name is shielded by court order - denied involvement and was shocked police would speak to him about a death he didn't know anything about, the inquest was told.
The man also contradicted evidence he'd given in 2015 but police are unsure whether the past user of the drug ice was suffering memory loss or being "deliberately untruthful", Sgt Kelly said.
Several of Mrs Harrison's seven children were in court to hear the evidence on Tuesday, with the coroner noting it was "a very sad occasion".
"Clearly, your mother was a very much-loved woman," Ms Ryan said.
