Arriving at their Kawakawa Bay home a short time later, he never came out to open the gate.
"I couldn't understand why he didn't open the gates, he always opened the gates when I came home. He was a thorough gentleman ... and then I wondered where he was."
His car was there, the house was wide open and the neighbours were outside. They said they'd spoken to him earlier. After walking around outside, she went inside, eventually finding him on the floor at his computer.
Campbell, a father of two boys and grandfather of two girls, had a pacemaker inserted in August last year after a quadruple bypass 10 years ago.
St John Paramedics assessed the pacemaker and told her the heart attack was so big, it wouldn't have mattered if she was home, he wouldn't have survived.
The 71-year-old's death had shaken their tight-knit family, especially after the death of Robyn's mother in January.
But she had been buoyed by friends he'd made all around the world, many in the rugby league community, who had been sending their condolences.
Campbell helped set up masters rugby league, which has since gone worldwide, and was involved in the sport for the disabled, universities, juniors, up-and-coming players - including helping discover Stacey Jones - Auckland Rugby League as well as his old club Ponsonby.
The masters' tournaments helped raise money for Middlemore Hospital's burns unit as well as cancer charities, including prostate.
"He lived a very full life and he just adored his grandchildren and watching Amber play netball and Maia play cricket."
His Facebook page had been inundated with condolence messages from other clubs and players, including former Kiwi Logan Swann.
Pat Carthy, Auckland Rugby League's football manager, has known Campbell for about 30 years.
"He certainly was a legend in the game. He was a former school control board [member], on the board of directors for Auckland Rugby League, managed many, many representative teams and organised overseas tours for a lot of the young players."
He originally played for Mt Wellington before moving over to Ponsonby.
"A lifetime involvement in the game and certainly a brilliant guy."
Unsurprisingly, Campbell was on the sidelines of the pre-season "Battle of the East" Pakuranga vs Howick on Saturday.
"He was a hard case, he had a great sense of humour and really focused on getting things done and making it happen. If you couldn't make it happen, Phil would make it happen."
Sir Peter Leitch also paid his respects, saying he "was a really good guy".
The pair knew each other through rugby league but became closer due to Masters' Rugby League donating to a charity close to Leitch's heart - prostate cancer.
"He will be sadly missed by a lot of people."
Friend of nearly 60 years, Fred McGregor, worked with Campbell on the masters tournaments.
He said the team had been left "utterly devastated" by his death.
"This man has left such a big hole in masters that I'm not sure how we're going to get out of that hole."
Although he never reached great heights playing, he was not only a manager with Auckland but also with New Zealand Rugby League. In that role, he toured with the Kiwis to Great Britain where he had a meal with the Queen.
Bruce Shaw, chair of Otahuhu Rugby League, has worked closely with Campbell on the masters games for 25 years.
He described his mate as "hard-working and energetic".
Campbell will be farewelled at Morrison Funeral Directors chapel on Wednesday at 12.30pm.
