Mr Tuhou was working alone on the farm, after farm directors John and Janet Frizzell went to a stock fair in Feilding for the day, the court heard.
The recent Worksafe figures showed that in more than half the 2015 incidents, farmers were aged over 55 and driving vehicles on sloping or uneven ground.
"These were mature and experienced people doing jobs they would have done many times before," said Al McCone, WorkSafe's agriculture programme manager.
"Examining vehicle fatalities from the last three years, we find that often the driver/rider had set out to do a fairly routine task like spraying or stock work."
The incidents had some common factors such as operators or others being hit by the vehicle, or being killed during a rollover.
"To keep yourself safe make sure the vehicle won't move when you get out, and wear seatbelts when in the cab or roll frame. Extra care is needed when working on or near slopes, especially on tracks with steep drop-offs."
The quads involved in the fatalities ranged in age and size, and were often in sound mechanical condition.
However, low tyre tread depth and under-inflated or uneven tyre pressure was noted as a possible contributing factor in some cases. Often the vehicle had slid on a slope and several incidents involved quad bikes overturning into drains, ditches or waterways.
"Good practice like keeping at least one metre from a stream or culvert edges, stopping and dismounting to spray, and working out 'no go' areas on-farm in advance could all help prevent incidents," said Mr McCone.
"Any vehicle is only as good as the way it is maintained and used. Make sure tyres and brakes, especially the handbrake on tractors, are in good condition, and it is essential operators know how to use the vehicles properly."
Farmers, both employers and employees, are also more likely to be working alone at busy times, so having a plan in place for lone workers meant if anything went wrong, the alarm could be raised.
"Like most risk management processes, it doesn't need to be complicated," Mr McCone said.
"There are a number of solutions that send out 'man down' or just location signals. If you can't afford these, then get a simple system in place where people check in at agreed times. If they don't, then check on them."
- For more information on staying healthy and safe on-farm, go to www.saferfarms.org.nz.
