The fatal injuries sustained by a baby in a Sydney car crash were not consistent with the infant having been in a child restraint, a jury has been told.
Peter Watfa is accused of driving with the 11-month-old baby in his lap, but he told police the infant was restrained in a baby capsule in the back seat.
The 43-year-old has pleaded not guilty to manslaughter by criminal negligence on February 25, 2019 at Lurnea, close to his Liverpool home.
Prosecutor Ken Gilson alleges the baby was in Watfa's lap when his BMW collided with a Mercedes, which was allegedly on the wrong side of the road.
He suggested the fatal injuries were caused by a combination of possibilities including impact with the BMW logo, with the steering wheel, the airbag and the force of Watfa's body being thrust forward.
Giving evidence in the District Court on Thursday, crash researcher Michael Griffiths said the baby's injuries were not consistent with him having been in a child restraint.
The results of many tests done up to speeds of 100km/h were that no injuries were sustained provided a child was harnessed, he said.
Forensic pathologist Dr Sarita Maistry said the cause of death was blunt force injuries to the baby's head, face and chest.
The baby had a large number of mainly bruises, but also abrasions, to his face, neck and trunk, as well as bleeding in the brain.
A patterned wound on the right side of the baby's face could have been caused by a BMW logo attached to the front of the steering wheel, she said.
"It is possible, it is that unique shape," she said.
Watfa's barrister Daniel Petrushnko asked if the pattern could have occurred when the driver was carrying the baby while removing him and the baby's head hit the steering wheel.
"If there was enough force to give an imprint," she said.
Deborah Cunningham and her daughter Georgia have testified to seeing the driver's door open and a man getting out with a baby in his arms straight after the crash.
"I suggest that the baby didn't exit the car at the same time as the driver, I suggest it was at a later time," Mr Petrushnko asked the daughter on Thursday.
"I disagree," she replied.
The trial continues.
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