A WorkSafe investigation later found Park had worked 197.25 hours in the two weeks leading up to the incident.
Fatigue was identified as the most likely cause of the accident.
The worker was also not wearing a seatbelt.
Agricultural Contractor Michael Vining Contracting Limited was charged in relation to Park's death.
Director Michael Vining pleaded guilty to failing to ensure the safety of workers and was sentenced last month in the Huntly District Court.
Judge Denise Saunders fined the company $10,000 and ordered it to pay reparation of $80,000.
It was the first sentencing for fatigue-related failings since the introduction of the Health and Safety at Work Act 2015.
WorkSafe said today that the company had a health and safety document prepared for them in January 2016.
The document identified fatigue as a high rating hazard and outlined management steps including the monitoring of work hours and break times.
"This document had not been reviewed or implemented," said WorkSafe spokesman Simon Humphries.
"The warning was there and the company did nothing about it."
Humphries said getting the job done was important - but not if the hours required to do it put workers at risk of injury or death.
"Seasonal work and tasks like harvest can put a huge amount of pressure on everyone involved," he said.
"Managing the risks is essential.
"The life, health and wellbeing of your workers must be your number one priority".
