SA trucking boss wins manslaughter appeal

An Adelaide trucking company boss will face a retrial after a landmark conviction for causing the death of one of his drivers was overturned.

Peter Francis Colbert was found guilty of manslaughter and endangering life and jailed for more than 12 years in 2015 for failing to repair faulty brakes on one of his trucks which led to the death of Robert Brimson.

On Wednesday the Court of Criminal Appeal set aside his conviction and ordered a new trial, citing the unfair summing up provided by trial judge David Peek.

The appeal court said Justice Peek's directions to the jury were unbalanced and his views pervaded his treatment of the prosecution and defence cases and witnesses.

"A reading of the entire summing up, in our view, does cause disquiet," the appeal judges said.

"It is significant that the judge undertook analysis on a number of occasions that had the effect of bolstering the prosecution case, in particular the evidence of the prosecution witnesses."

Mr Brimson, 45, died when he hit a pole after desperately pumping his failed brakes and veering away from other motorists.

The trial heard another driver had experienced a near miss in the same truck not long before the fatal crash.

In sentencing, Justice Peek said Colbert maintained he knew nothing of the faulty brakes despite multiple witnesses saying he did.

The judge said a substantial prison sentence was required to deter other truck companies from dangerous negligence.

He jailed Colbert for 12 years and six months, with a non-parole period of 10 years, and also banned him from driving indefinitely.

The verdict was believed to be the first time in SA a company owner had been held criminally responsible for an employee's death because of negligence.