However, despite modification, police said it was unclear what caused the van to crash.
In February 2020, Leitch and a group of eight people decided to travel to Queenstown.
On their return to Invercargill about 4.30am the next morning, the driver, Aaron James Collinson, left Winton.
A short time later, while negotiating a slight left bend, the vehicle drifted across the fog line and into the water table ditch on the side of the road, causing the van to flip and roll about six times before coming to a stop.
The driver and a passenger remained in the van secured by the seat belt but the other seven occupants of the car - including Leitch - were all thrown from it at various locations.
During the rolling, the front uncertified bench seat in the rear became dislodged, and began rolling.
Newport was thrown from the van and her body became trapped under the vehicle on the driver's side. She died at the scene.
During the court hearing today, judge Russell Walker took note of his guilty plea but adjourned the matter until Leitch attended the Right Track programme — a course provided to show dangerous drivers the possible repercussions of their actions to prevent them from reoffending.
Judge Walker also suggested the man complete 150 hours of voluntary community work until his appearance for sentencing, which was yet to be scheduled.
A nominal date was set for November 30, when Leitch's defence lawyer, Tanya McCullum, will update the judge on her client's progress.
