Constable Adam Blummont suffered a fractured leg, knee injuries, facial cuts and concussion when he was thrown to the side of the road on impact.
Crown prosecutor Rebecca Guthrie told the court the main issue was whether it was deliberate, but Crown witness Alana Mumby, who had been in the car, said she was driving, having previously told police she wasn't.
Mr Gilmore pursued the car as it left. He later found it abandoned near a paddock where a police dog tracked Ms Mumby. Richards was arrested on the night of December 19.
Constable Dwayne Coffin, who manned the main alcohol checkpoint on the Napier side of the Clive Bridge, said the reason drivers slowed down and turned off was usually because they wanted to avoid police.
"I heard a very large bang and put two and two together and realised Adam had been hit," he said. "Constable Blummont was lying on his back on the side of the road. He was in shock, he was shaking, he had a large laceration on his forehead, his pants were ripped, he was complaining of injuries to his legs, he was quite a mess. It was quite a traumatic time."
The prosecution case ended late yesterday, and the jury is expected to retire to consider a verdict today.