Allegations that a teenage defendant was in the wrong lane during a crash last year make “no scientific sense”, according to a retired police collision investigator.

Jahni Holder, 19, from Ridgeway Road, Pembroke, has admitted driving a motorcycle without a licence or valid insurance, but has denied causing grievous bodily harm while driving without insurance or a licence, and driving without due care in connection to a traffic collision on November 9 last year.

Prosecutors have alleged Mr Holder was travelling west in the eastbound lane of South Road in Warwick when he crashed into 17-year-old Rashaun Zuill near Marley Beach Cottages.

Mr Zuill, who is still receiving treatment overseas, broke his jaw, right arm, right wrist and right leg and suffering a punctured right lung and road rash in the crash.

Police collision investigator Emerson Carrington said earlier this week that based on scrape marks found at the scene and the spread of debris, Mr Holder’s motorcycle struck Mr Zuill’s head on in the eastbound lane, with Mr Johansen’s vehicle becoming involved moments later.

But as the trial continued yesterday, collision Inspector Gary Venning said: “I totally disagree that the accident could have possibly happened in the eastbound carriageway. It makes no scientific sense.”

Mr Venning said while he did not attend the scene on the night of the crash, he used pictures taken by investigating officers and witness statements in an effort to piece together what happened.

He argued that while the majority of debris was spread in the eastbound lane, if the collision had taken place in that lane debris would have been flung onto the sidewalk and nearby bushes by the force of the crash.

And he said that because of the bend in the road, Mr Zuill would have had a very poor line of site if he was riding in the wrong lane, but Mr Holder would have had a very good line of site if he had been in the wrong lane.

Mr Venning said that based on the damage caused by the collision, it was likely that neither vehicle was travelling at excessive speeds, but because of the nature of the bend in the road they wouldn’t have had enough time to avoid a collision.

“If Mr Holder came around the bend and was confronted by a cycle or cycles over taking in the westbound lane, a collision was inevitable and almost unavoidable, other than maybe by luck because the amount of time available wasn’t enough for either rider to either brake or take avoidance actions,” he said.

Mr Holder also testified, while wearing a sling on his right arm. He told the court he was driving west along South Road in Warwick on the way to a friend’s house when the crash took place.

“I was coming around the Swizzle Inn where the line turns white. I had overtaken a car and was back on my side of the road,” Mr Holder told the court.

“These boys were on my side of the road. I tried to go left, but there was nothing I could do. We collided.”

He said the impact rendered him unconscious.

Under cross examination, he disagreed that he could have taken a taxi or a bus rather than ride an unlicensed and uninsured motorcycle on the evening of the crash, saying he didn’t want to wait for a bus and he didn’t have enough money to catch a cab.

He denied that he was faster than 40 or 50kph when he came around the bend by the Marley Beach cottages or crossing into the eastbound lane, saying: “There was no reason for me to enter it.”

The trial is expected to continue today.