The court heard that, to dismiss him, the company had relied on a paragraph that said he had deliberately refused to wear a bump-hat, which was part of the personal protective equipment requirements.
The hat was introduced in December 2014 and, with hot Hawke's Bay summer temperatures, Mr Kupa said at times he found it too hot to wear. When his lawyer asked him what impact the hat had on his work, he said: "You get dizzy and faint-headed at times ... you slow down."
One witness said Mr Kupa was just "one of many" who found it uncomfortable to wear in the heat.
Since being dismissed, he said, he had struggled to find work - it was difficult to tell people he had been dismissed from a job he had been doing for so long.
He had several children to support and the added stress had a huge impact on his personal life.
Mr Kupa had worked with cattle beasts, which hung from chains in front of him.
There was lots of blood, water, fat and bones in the workplace, the court heard.
The respondent's lawyer, Tim Cleary, said a notice had been displayed in the workplace for several months saying if someone was struggling with the heat they must talk to a supervisor.
Mr Cleary told Judge Bruce Corkill that workers were told if they failed to wear the hats, as required under health and safety, they would be held accountable.
Heavier duty hard hats were also worn in other areas of the plant, as required.
Mr Kupa said he did not think it was unreasonable to wear the protective hat but it was hot and affected his and others' work.
The second witness, head of union representative, Eric Mischefski , pointed out the warning label on the hat while giving evidence.
He said in his opinion the hat did not qualify as personal protective equipment because of its inability to shield falling objects.
Mr Mischefski said the combination of heat and humidity made the work difficult but had been told fixing the heat issue was "outside the budget".
Another witness, who worked alongside Mr Kupa, said since the hat had been introduced the rules had changed a number of times, they were "flexible" and it had become confusing when they were required and when they were not.
Before his dismissal, Mr Kupa was stood down on March 25 last year following an incident involving visitors to the plant.
He said management had told him he must leave his hat on until the visitors had left. He took the hat off when the visitors left, but they had backtracked and caught him without his hat.
Mr Cleary put to Mr Kupa that he could have chosen to follow proper protocol and tell his superior he was feeling unwell and needed to take his hat off.
Some witnesses corroborated this, while others said they heard a different message instructing them to keep their hats on until morning smoko.
A number of the witnesses said messages were often relayed to each other down the line instead of formal announcements.
- The hearing will continue today and is expected to finish tomorrow.
