"He had fallen, his body was blocking the door, his full weight was against it and I couldn't get it open.
"I could just see him through a crack in the door, I could see that he was gone.
"It was really, really traumatic."
Nairn's death was referred to the Coroner and an inquest held across several days in August and September.
Coroner Sue Johnson released her findings publicly today.
She said she was satisfied with the evidence presented to her that she had sufficient information to establish the cause of Nairn's death.
However she still needed to consider and establish as part of a "wider inquiry" whether Nairn's death could have been prevented and if she needed to make any recommendations.
Rory Nairn and fiancee Ashleigh Wilson. Photo / Supplied
"My inquiry into these latter issues at is still ongoing," she said.
"Given the public interest in whether or not Rory's death was related to the Covid-19 vaccination he received on 5 November 2021, I consider it important to make public my findings as to the cause of Rory's death as soon as I established it."
Wilson said she did not want to speak about the Coroner's findings at this stage.
"She stated that the cause of the myocarditis came down to a diagnosis by exclusion."
Coroner Johnson said there was is no test at the moment that showed the Covid-19 vaccine in myocardial tissue - but Hung was able to exclude the other causes of myocarditis.
"For example, she saw that it was not caused by Rory having rheumatic fever or by infection as there was no sign of a bacteria, virus or fungi," the Coroner said.
"She also excluded all other known potential causes of myocarditis, for example certain medicines such as the anti-psychotic medications clozapine and risperidone which can cause myocarditis.
"Dr Hung also microscopically examined minute tissue samples she took from other parts of Rory's body: his lungs, thyroid, pancreas, liver, spleen, bone marrow, adrenal glands, kidneys and the central nervous system.
"There was no sign of any infection or any other reason for Rory's death except in the myocardium."
Coroner Johnson said based on Hung's evidence she was satisfied Nairn's cause of death had been established.
"In view of symptoms since Covid-19 vaccination, and no other cause for myocarditis identified, the myocarditis is consistent with vaccine-related myocarditis," she said.
"I accept Dr Hung's medical opinion that the direct cause of Rory's death was acute myocarditis and that in the absence of any other cause for the myocarditis being identified by the numerous tests that Dr Hung carried out or caused to be carried out, the myocarditis is consistent with vaccine-related myocarditis.
"I am satisfied that Dr Hung's evidence is sufficiently clear, cogent and exacting for me to infer from it that vaccination with the Covid-19 vaccine caused the myocarditis from which Rory died."
Rory Nairn and Ashleigh Wilson were engaged to be married. Photo / Supplied
Coroner Johnson reminded that her inquiry into Nairn's death was ongoing.
"I find that… the cause of his death was myocarditis, due to vaccination with the ComirnatyTM Pfizer/BioN Tech Covid-19 vaccine," she said.
She hoped sharing his story would spark more awareness around the vaccine, what people should watch out for in terms of side effects and when they should seek medical help.
"Rory wasn't worried about his symptoms until that night. But if you have symptoms to do with your heart you really need to get to hospital to get answers."
Wilson hoped people would take their health more seriously after reading Nairn's story.
"Rory was a really typical Kiwi bloke - he never complained and he was always happy and humble.
