He had analysed the raw data taken from the CCTV footage frame by frame and also at pixel level to ensure he had eliminated potential irrelevant data.
Dr Calhaem said he was able to calculate the position of the vehicle on the road and its average speed going up the road at 65km/h. He calculated the same vehicle travelled back down the road 1.5 times faster.
Dr Calhaem said before braking, the vehicle's velocity was calculated at 132km/h "give or take 40km/h" and after braking 117km/h (plus or minus 40km/h), for an average velocity of around 100km/h.
He was able to determine the position of the car and the victim at the point of impact.
Dr Calhaem said the driver-side wheels came within the median strip on the return trip down the road, and the victim, who was walking along with his foot on the edge of median strip, had taken one step.
"However, the headlight beams of the vehicle would have reached the victim well before the brake lights went on. At least one car length.
"We can see immediately prior to impact, the person, the victim standing on the road, well lit by the headlights," he said.
During cross-examination, Green's lawyer Tony Rickard-Simms put it to Dr Calhaem that the difficulty with his conclusions using the CCTV footage was that the jury was being asked to rely on distorted images. Dr Calhaem said any distortion would be consistent across all of the images, and he had also used the ESR data and personally measured from the CCTV cameras to the point of impact.
The defence put the victim close to the median line and also taking a significant step towards the car before impact, Mr Rickard-Simms said.
Dr Calhaem said he would not say it was a significant step, but the victim moved his right foot back towards the centreline just before impact.
The trial continues today.