Wife Heather thought her 63-year-old husband was having a heart attack and called their daughter Bex, a registered nurse. An ambulance rushed him to hospital but, by the time he arrived, his body had started to shut down.
Blood results revealed severe staphylococcus aureus septicaemia. The infection caused major organ failure.
First Mr McAlley's kidneys failed and he was placed in Tauranga Hospital's ICU (Intensive Care Unit), where he stayed for five weeks in an induced coma and on a ventilator.
A host of issues followed, including pneumonia; a mitral valve vegetation (an inflammation of the inner tissue of the heart); a bowel obstruction; a severe bowel infection, C. Diff (Clostridium Difficile); ulcerations; haemorrhaging necessitating 32 units of blood to be transfused; loss of skin; loss of weight (18kg); muscle wastage; respiratory problems necessitating a tracheostomy (opening a direct airway through an incision in the windpipe); and discitis (an infection in the intervertebral disc space).
Having been transferred to the Acute Renal Unit at Waikato Hospital, Mr McAlley received the first indication he was on the mend.
"After four sessions of dialysis the duty doctor was looking at my tests, turned around and said 'you don't need dialysis', because my kidneys had kicked in. I just cried."
This weekend, after four months and three days, the former BNZ bank manager returned to his Matua home. He said he felt profoundly fortunate and grateful.
"The most telling thing in the whole experience for me was the love of my family," said an emotional Mr McAlley.
"Heather spent time lying on a mattress on the floor in Waikato Hospital to be with me at night."
For the first four days in Tauranga Hospital's ICU, Mr McAlley's family - wife Heather, son Mark, daughter Bex and brother-in-law Trevor - did not leave his side.
He also praised the care of the Tauranga and Waikato Hospital nursing staff.
"The staff were absolutely amazing. They went to the end of the trail to try and keep me going. Even to the extent of nurses doing double shifts just to care for me."
Mrs McAlley, a nurse in Tauranga Hospital Special Care Bay Unit, said: "We couldn't believe it had happened to a healthy 63-year-old man who is passionate about sport, doesn't smoke, drinks in moderation. It was all very surreal."
Toi Te Ora Medical Officer of Health Dr Phil Shoemack said that, while such cases were not common, they could be difficult to guard against.
"Our environment is not sterile and neither is our skin."