A truck driver faced four juries before he was found guilty of dangerous driving causing death, it can now be revealed.

In a case that highlights the strain that aborted trials put on the judicial system, it can now be reported that three juries were discharged in February and March in the case of David James Ross, before a fourth jury found him guilty.

Two of the juries were dismissed soon after lawyers had made their opening presentations of their cases and one was discharged after having heard evidence for a week because the prosecution argued that Ross's defence was run incompetently.

Ross, 49, fronted a pre-sentence hearing in the County Court on Wednesday following his conviction over the death of Dianne Beel, whose car was hit from behind on the Hume Freeway, near the Donnybrook overpass on Melbourne's northern fringe, on March 3, 2010.

Ms Beel, 59, died at the scene after Ross's semi-trailer crashed into the back of the car. The court previously heard Ross' truck hit the car at between 90km/h and 100km/h, when vehicles were required to slow for road works.

It can now be reported the initial trial was aborted after the opening addresses when a juror was upset after hearing details of the crash, and judge Paul Lacava ruled the juror's distress could be prejudicial against Ross.

The third jury was also dismissed not long into the trial, after a juror recognised a lawyer who was sitting in court on behalf of Don Watson Transport, which employed Ross at the time of the crash.

The second trial was aborted on legal grounds, when prosecutor Bruce Nibbs argued that Ross's defence was incompetently run, as several of the defence's expert witnesses had given evidence that conflicted with reports they had written that had earlier been presented to the court.

Mr Nibbs argued at the time the contrast in evidence given by defence witnesses had confused the jury, and that the way the trial was run opened the verdict to the possibility of an appeal.

Judge Lacava said at the time the trial had descended into "a war of experts" that had overly complicated and prolonged the hearing.

But judge Lacava ruled Ross's defence counsel, Bradley Newton, was not incompetent and had "conducted himself in the finest tradition of the Vic Bar".

The fourth jury last month found Ross guilty of one charge of dangerous driving causing death.

The court heard on Wednesday there were no signs of alcohol or drugs in Ross's system and no evidence he had exceeded the speed limit, had veered out of his lane or been on a mobile phone at the time of the crash.

Mr Newton said Ross's moral culpability was at the lower end of the scale, and agreed with judge Lacava's summation it was a case of a driver failing to keep a proper lookout.

But Mr Nibbs said it was improper to argue Ross's culpability was at the lower end.

"This is a situation where a person is driving a semi-trailer with a better field of view, knowing that he needed longer time and greater distance than a car to brake, with a perfect line of sight, in clear weather and in daylight, and failed to look at the scene in front of him," he said.

The court heard Ross had previous convictions for drink-driving in Western Australia and for driving when his licence was suspended in Victoria.

Mr Newton told the court prison would be onerous on his client, as Ross had mental-health problems and required daily treatment for burns to his body he suffered when he was a young man.

Ross is in custody and will be sentenced at a later date.