His sick 2-year-old daughter was in the car when Mau, who was a disqualified driver at the time, drove both men to Cafler Park and waited for their return following the robbery.
Mau had taken time off work that day to look after his daughter when he was asked that morning to drive for the men.
In sentencing Mau, Judge Keith de Ridder adopted the same starting point as that of Mau's half-brother as he treated both as being equally culpable of the crime.
The judge followed the guideline case of the Court of Appeal, known as R v Mako, with the court saying getaway drivers played a crucial role in armed robberies by providing the principal offenders with the assurance they could speedily escape.
After allowing discounts for time Mau spent on electronically-monitored bail and his guilty plea, Judge de Ridder arrived at an end sentence of five years and four months.
Mau argued in the Court of Appeal that he knew nothing of the robbery until after he collected his younger half-brother, nor of the weapon until he saw the principal offenders return to the car after the weapon had been used.
The sentencing judge, Mau argued, should have allowed him discounts for his cultural and personal circumstances, and the impact his incarceration would have on his family.
The court said while Mau must still be held accountable for his role in facilitating the offending by serving as the driver, his culpability in the case was substantially less than that of his co-offenders.
"Unlike his co-offenders, Mr Mau's involvement was substantially unpremeditated and he did not fully appreciate the risk of harm to the public until after the weapon had been used," the Court of Appeal said.