Investigator Alun Mills said finding a cause of the tragedy has been made harder by the fact Brock's highly skilled driving showed little variation at critical stages.
Brock's braking, acceleration and use of gears - among other indicators - were remarkably similar at comparable places throughout the Targa West Rally stage outside Perth.
Sen-Constable Mills, of West Australia's major crash investigation section, said Brock took corners similar to that on which he died within a 1km/h range of speed.
"It's not like he's gone into the other corners at 40km/h and done this one (the fatal corner) at 80km/h," he said.
Sen-Constable Mills said the exact cause may never be known and his office may need to present the coroner with a range of scenarios.
"It's like a computer driving the car. You're trying to find something that's not normal in his driving and it's not there," Sen-Constable Mills said.
The case shapes as one of Australia's most detailed crash investigations.
Data from the high-powered coupe's black box recorder, which logged every performance indicator, is still being retrieved as investigators try to get a more precise picture of what happened.
Video footage shot from within and outside the Daytona on September 8 is also being utilised.
Police are yet to receive the results of a survey they did of the corner where Brock lost control and slammed into a tree.
Sen-Constable Mills said the survey's detailed recording may help find answers to why Brock crashed at a speed at which he safely negotiated other corners.