A Sydney police car swerving in and out of traffic without indicating crashed into a grandmother's car with such force it appeared both lifted off the ground, a jury has been told.
Kamil Kozlowski had been driving on his L-plates just two weeks when he witnessed Senior Constable Harry Thomas Little's highway patrol car slamming into a Mercedes in September 2018.
The 42-year-old police officer has pleaded not guilty to dangerous driving occasioning grievous bodily harm.
Sydney woman Gai Viera had been turning right onto Cronulla's six-lane Kingsway at the same time Little was chasing down a Volkswagen whose driver was suspected of illegally using their mobile phone.
A baby in the backseat of her car was uninjured in the crash but Ms Viera suffered a brain injury "from which she will likely never recover", crown prosecutor Carl Young told the District Court earlier.
Mr Kozlowski had seen the police car speeding up in his rear-view mirror before switching lanes to pass directly in front.
He observed no indicator, no lights and no sirens.
Nor did his mother Marta who was teaching him how to drive when she also saw the police car swerving among traffic.
But she distinctly remembers the moment of impact as both cars appeared to be lifting "up from the street".
"Because it was so strong both cars went off the ground at the moment of the hit and collision," she said.
It's agreed that Little accelerated quickly to 122km/h, "braked heavily and slowed" to about 73km/h to move around the L-plater and then accelerated again once back in the right lane.
The police car was recorded at 135.4km/h about one to two seconds before impacting Ms Vieira's car.
Defence barrister Hament Dhanji SC questioned why Mr Kozlowski's police statement at the time said he "didn't think he used any indicators".
"Does that show you weren't sure?" he said.
"I remember now I didn't see any indication," Mr Kozlowski responded.
Earlier the trial heard from experienced highway patrol officers who were called to the incident.
Sergeant Garth Quin heard a high-pitched screaming down the radio and thought it might be a prankster, before the message "person trapped" transmitted.
"Then we realised we had a situation on our hands," he said.
Minutes later he found Little in his police car very distressed with cuts around his face and worried for the other driver.
"Make sure she's OK, get her out," Little told him on arrival.
"He was very distressed and in a very emotional state.
"He was more concerned with her than himself."
Little truly believed he had switched on his lights and sirens after passing the L-plater, his defence has argued.
Sgt Quin said he had on a number of occasions tried to activate his police car lights but failed to do so.
If the panel button was not pressed on the centre and firmly, "you don't get activation," he said.
The trial continues.