The driver's door was open while Mr Hoani was warming up the engine, as another employee, Mr Kingi, was manoeuvring his truck out of the yard and hit the side of the open door.
Afterwards, Mr Kingi agreed to let Mr Hoani use his truck to start his haul to Wellington, said the ERA finding.
Mr Hoani did not report the damage to management because he thought it was Mr Kingi's fault, he said.
When he returned to Marton later that day a discussion between Mr Hoani and company director Wiremu Abraham over him taking upcoming holidays became heated, and ended with Mr Hoani being told the company was restructuring and he was dismissed on one week's notice, he said.
But Mr Abraham gave a different version of events.
He had learnt about the truck damage from Mr Kingi who said Mr Hoani had "threatened and bullied" him and forced the truck swap, he said.
When questioned, Mr Hoani refused to discuss the matter, said Mr Abraham, then decided to dismiss him over it.
It was not the first time Mr Hoani had been dismissed from the company, said the ERA finding.
A year earlier, in 2010, he was dismissed for having returned a positive test for cannabis use. After a stand-down period he was "given another chance" and re-employed by the company, said Mr Abraham.
Authority member Michele Ryan found Mr Abraham was justified in dismissing Mr Hoani for serious misconduct over the truck damage, saying the driver had "overwhelmingly contributed to the situation that led to his dismissal", she said.
"I assess Mr Hoani's contribution to the situation that led to his dismissal as 90 per cent."
But by failing to warn him of the possible consequences of him not explaining the incident or allowing him to get assistance over the matter, the dismissal process was unfair, Ms Ryan found.
Because of his actions, Mr Hoani's compensation for his personal grievance claim was reduced by the ERA from $5000 to $500.
The company was also ordered to pay a further $1393.55 for unpaid wages for work carried out during his time with the company.
