Around September 4, the defendants met at Thomson's Paengaroa property where he tried to castrate the bulls using the standard process of tightly fitting an approved rubber ring or elastrator band to the neck of the animals' testes.
When he was unable to do so, due to the size of the bulls' testes, Thomson loaded the bulls onto a trailer and drove to a nearby service station car park in Paengaroa with Green following.
After buying cable ties and some thick rubber bands from the service station, Thomson again tried to castrate the bulls by placing the rubber bands around their testes.
He then applied the cable ties over the bands attempting to hold them in place.
Thomson did not use any anaesthetic.
He told Green that the bulls' testes would eventually fall off in about eight weeks, and if this did not happen he would do the procedure again.
Green then drove the trailer with the bulls to his property in Whakamarama.
On October 16, the SPCA received a call of concern about two bulls on Green's property which appeared unwell and an SPCA inspector and a veterinarian visited to inspect the animals.
SPCA said it was immediately apparent that the bulls were infected in their testes area and a putrid odour could be smelt from some distance away.
The bulls were sedated by the veterinarian and the infected testes surgically removed.
SPCA said the vet who treated them confirmed that due to the incorrect castration method, and the ineffective tourniquet, the bulls should have had immediate treatment.
Their testes developed severe infections, including gangrene and sepsis, which would have caused the bulls undue pain and distress.
Green told the SPCA inspector that he didn't believe anything was wrong with the animals and they seemed content and happy, from what he could see.
He also told the inspector he was waiting the eight weeks after the castration attempt to see if the testes would fall off, as Thomson had advised him to do.
The vet provided clear post-operative care advice and told Green to call the clinic if any
concerns arose.
Subsequently, one of the bulls developed sepsis and was euthanised.
Thomson has pleaded guilty to two charges under the Animal Welfare (Care and Procedures) Regulations Act 2018 relating to castrating a cattle beast aged 14 months with a high tension band without pain relief.
The maximum penalty for each charge is a fine of $3000.
Green had admitted two charges of failing to ensure an animal that was ill or injured received treatment which alleviated any unreasonable or unnecessary pain, or distress.
The maximum penalty for this offence is 12 months' prison or a fine of $50,000.
SPCA's lawyer Emma Pairman argued before Judge David Cameron the level of culpability for each defendant was high and at a similar level despite Thomson having carried out the castrations.
Pairman sought a maximum fine of $3000 per charge for each defendant before any mitigating factors and guilty pleas were taken into account.
She described the matter, in her opinion, as "one of the most serious offences" of its kind, given the bulls' age meant the animals should not have been castrated using this method at all.
Also, the fact that no pain relief was administered and no follow-up veterinary care sought were aggravating factors, Pairman said.
SPCA has also sought reparation for the veterinary bill and the charity's legal costs.
Green's lawyer Duncan Wilsher said his client, who was not an experienced farmer, was "incredibly remorseful" and had relied on Thomson's advice.
Wilsher also argued that Green was less culpable than Thomson, and his offending was at the lower end of the scale in terms of its gravity compared to similar prosecution cases.
Thomson's lawyer Patrick Anderson argued that the SPCA's starting point for the fine was "too high" when compared to penalties imposed for more serious prosecution cases.
Anderson told Judge Cameron that his client was "quite humbled and quite embarrassed" to be appearing before the court, particularly given his previous job as a police officer.
"I'm quite confident that Mr Thomson won't be back before the court again."
Anderson said Thomson was "very stressed" at the time he performed the castrations offence and there was "no wickedness or ill-intent" behind his actions.
"I would categorise his offending as a 15-minute rash moment of madness while under pressure. Mr Thomson knows he got it wrong and very much regrets it," he said.
He urged the judge to take into account Thomson's previous good character and his many years of community service, including with the police and the territorial army.
Judge Cameron reserved his decision.