Rachel woke him at 1am on the Tuesday, concerned he was struggling to breathe and panting. Sean says it was like trying to breathe through a straw.
"I tried breathing slow and deep, I tried breathing fast and hard, but I could never feel like I was getting a lung full of oxygen."
An ambulance took Sean to Taupo Hospital, where he continued to deteriorate.
"I felt like I was freezing. My teeth were chattering, I was shivering, but my temperature was going through the roof."
By the morning, Sean, now lacking oxygen, sleep-deprived and weak, was transferred to Rotorua Hospital's intensive care unit, where doctors and nurses struggled to find enough veins for nine different needles and arrest his plummeting blood pressure. Meanwhile, his oxygen absorption continued to drop.
At the same time it seemed incredible to the 44-year-old that he could be in serious danger.
He knew something was wrong, but he kept telling himself it was a bug that doctors would soon sort out.
The next night was the worst of Sean's life.
"I couldn't breathe. I ripped my [oxygen] mask off, felt I was going to die and I pushed a nurse over. They got security to hold me down while I had the mask on, and the nurse talked me through my breaths for about three hours."
The next morning, Sean's family was summoned because doctors doubted he would make it through another night.
"That really, really freaked me out. I started crying. I picked up my phone and was looking at pictures of my kids and my wife and showing the doctors.
"I did ask, 'Is there a chance I might not wake up from this?' and they said yes. I had the good sense to tell my wife I love her. It was freaky, going through the process that might be the end."
The doctors intubated Sean (put a tube in his throat to help him breathe) and put him into a medical coma to try to stop the virus that had attacked his heart, with his left ventricle only operating at 25 per cent capacity. His lungs were full of fluid and he was dying. His family were summoned to his bedside and from there it was a waiting game.
The doctors' action paid off. The coma worked by giving his body a chance to recover.
Doctors revived Sean after two days and three days later he was moved from intensive care to the coronary care unit. He spent two weeks in hospital and went home on his wedding anniversary. Doctors told him if he was a smoker, he would have died.
Sean was keen to return to work but Cobb & Co told him to take his time and recover fully.
He was off for two months and eased himself back into work.
Sean says doctors were unable to tell him what had made him so sick. Tests all came back negative, meaning either the virus could not be detected or had gone. But given how soon it occurred after him handling compost, and that his sickness fitted with the symptoms in the health warning on the bag, he suspects it was legionnaires', which can be transmitted in potting mix, compost and water systems.
His children were too young to realise what was happening, although Coby, 3, came to visit Sean in intensive care - where he tried to press all the machines' buttons and even pulled out a plug - and Sean says he has made an effort to be completely present when he is with them.
"When you're with kids and they're fascinated with a flower, to really look at it and stop and slow down, it makes you realise that life is precious ... which sounds so corny."
His other message to people is to take care with compost and potting mix, to read the instructions and warning labels.
Sean says Rotorua Hospital and the New Zealand health system came through for him when he needed it most and he is thankful for the care he received.
"When push comes to shove, they are there for you."
