A former trainee soldier has been found not guilty of dangerous driving causing the death of a colleague during a training exercise at Sydney's Holsworthy Barracks in 2012.

Alexander Gall, 24, was accused of seven serious offences, including dangerous driving causing death.

The 2012 crash killed Sapper Jordan Penpraze and seriously injured six others who were all on board the six-tonne personnel vehicle, known as a 'Unimog'.

The then-20-year-old had been a trainee soldier for just over seven months and was still on his civilian L plates at the time.

Witnesses said he was speeding and driving recklessly at the time but his lawyers argued the Army's training of Gall had been hopelessly inadequate and its supervision virtually non-existent.

Sapper Jordan Penpraze died from injuries sustained in the truck accident. ( Australian Defence Force )

Sapper Dylan Williams, who was injured in the crash, previously told the court that he could "feel" that Gall was aiming at potholes in the road and driving recklessly.

Mr Gall stood with his hands clasped in front of him as the foreman of the jury was asked to deliver its verdict on the first charge of dangerous driving causing death.

"Not guilty," the foreman replied firmly.

Mr Gall lowered his head and fought back tears.

The foreman was then asked for a verdict on each of the following six charges of dangerous driving causing serious injury.

"Not guilty," he replied to each one.

In the public gallery, the former soldier's mother and partner sobbed and supporters said that "justice had been done".

Mr Gall made a short statement to the media outside the court, apologising to the families affected by the accident.

An Australian Army Unimog truck like the one in the accident. ( ADF: LAC Rodney Welch )

"I'm deeply sorry for the pain and loss that I've caused the Penpraze family," he said.

"Not a day has gone by when I do not wish that I could have those moments back so that they could have their son back.

"I'm so deeply sorry to all those passengers and anyone else involved."

The father of Sapper Penpraze was in court to hear the verdict.

He left the court complex immediately afterwards without making any public comment.

During the trial, Mr Gall's defence barrister David McLure SC told the jury that Mr Gall had only completed an Army vehicle driver training course a month before the accident.

He said that course involved 13 days of driving, with 14 hours of that specifically spent behind the wheel of a Unimog vehicle.

"The Army's training of this young man was hopelessly inadequate and the supervision was almost non-existent," he said.