"You punched him in the right side of the face using a closed fist and again to the left side of his face and punched at him a third time, but missed him."
Peeti also attempted to pull the man from his truck, but failed to do so.
As a result of the attack, the 80-year-old victim required medical attention, suffering a swollen and bruised neck, as well as a bruised and cut eye.
Defence counsel Roger Crowley said his client had "just lost his cool".
"He feels he's let himself down, he's let his family down and that's a fair assessment of where he is," Crowley said.
"The consequences of that brain explosion were severe, significant, undeserved and unnecessary."
He pleaded guilty to a charge of injuring with intent to injure with reckless disregard.
Judge Field sentenced him to three months' community detention and 100 hours' community work.
He also ordered that Peeti pay $500 emotional harm reparation.