Despite Tackney exceeding the speed limit — police estimate he was travelling 68kmh-70kmh in a 60kmh zone — it is alleged the defendant had time to see him and avoid the smash.
Serious crash analyst Constable Jack McGilbert told the court Walsh would have had about 3.7 seconds from starting her turn into Brighton Rd to the point of impact with the motorcycle.
Counsel Joe O'Neill said his crash expert would later give evidence the average time, based on watching 50 people use the intersection, was 2.4 seconds.
Const McGilbert said he disagreed with some of the methodology his counterpart had used in arriving at his various conclusions.
Yesterday, pathologist Dr Leonard Wakefield also gave evidence.
Judge David Robinson warned family members in the public gallery that what was to be discussed was not the sort of thing that could be "unheard".
Such was the extent of Tackney's injuries, it took the witness almost half an hour to detail his findings from a postmortem completed a couple of days after the incident.
The victim, Dr Wakefield said, died from "high-energy impact injuries".
The court had previously heard the death was specifically down to a ruptured aorta and the pathologist found 75 per cent of its circumference was torn in the crash.
Tackney suffered fractured vertebrae, nose and forearm, as well as numerous abrasions from sliding down the road after he and the bike fell to the right.
One of his wrists was broken while the other hand was almost completely detached, the court heard.
Tackney was found to have a "badly lacerated" liver, a "deeply" torn spleen and haemorrhaging in both kidneys.
There were no significant findings when it came to alcohol or drugs in his system.
It was the same for Walsh.
A nearby resident who rushed to perform CPR on Tackney said she later heard the defendant ask where the rider had come from.
"I didn't see him, I didn't see him," she allegedly repeated.
O'Neill said one of the causative factors was that Walsh's visibility had been impeded by a parked car.
The trial, held without a jury, will hear from the defence's crash expert before Judge Robinson decides whether the charge has been proven.