For the disbelievers, almost including the man himself, the evidence of the last week is all there.
There's the weekly golf results in Hawke's Bay Today with his senior men's stableford, there's no doubt it was really him on the course yesterday, and then there's video footage of the surprisingly short Friday evening battle off Opal Ridge, 48 nautical miles north of Cairns.
He'd been hoping to keep it quiet, but with Melbourne-based son Grant and Cairns charter fishing operator Daniel McCarthy both on the go that was never likely. It's gone global.
"He's setting me up," Mr Perry said at home in Napier before heading out for the golf course, after Grant had told Hawke's Bay Today of the event, and the Lotto-sized odds of this man and that fish being in the same place at the same time.
"It was awesome," said Grant Perry. "It was a monster. the pictures do the size no justice at all. It hit the bait (the size of a kingfish), and swallowed it like a whole freight train."
It was Grant who said "Come on, we're going fishing," it was Grant and brother Frazer with whom Mr Perry set-out on the charter vessel Moana III the morning after arriving in Cairns, and it was Grant who should have gone into the fisherman's chair first.
Doug Perry said: "It was all new to me. I've never been in the chair, I've never chased marlin before, but Grant said: 'No, you go first."
Once hooked, it took just 15 minutes to bring it to the boat where it was tagged with a leftover tag from a recent Lizard Island Game Fish Club tournament, the line cut and the half-tonne monster left to disappear into the ocean.
Mr Perry said it was team effort, highlighting the skill and knowledge of skipper McCarthy and deck-hands "Roger and Jason," and an almost compliant black marlin.
"It almost ignores you," he said. "It knows it's got something in the side of it's mouth, but it just doesn't know how to get it out."
Mr McCarthy had seen arm-stretchers of the ocean before, but this was rare, and mind-boggling.
"How's that for luck," he said on-line. "He's out there, and on his first go, he catches an absolute goliath."
The marlin was estimated to be about 30 years old, and almost certainly female, the prime reason for its release in a conservation project in which sport fishermen, boat captains and biologists have been working together to tag and release black marlin for research and species survival purposes, rather than killing them.
As for Doug Perry's golfing mates, last night they were still none-the-wiser. Known for his modesty, he hadn't mentioned a thing about it all day. Afterwards he toddled off home "to cook tea for the missus," but it wasn't fish.
