"I saw his face in the paper and thought, 'if it wasn't for you, my little fella wouldn't still be here and there's a good chance that I wouldn't be here'."
The Whakatāne man was the first person confirmed killed after Monday's volcanic explosion.
In January 2016, Paterson and his two boys went on a guided tour of Whakaari/White Island.
Hayden Marshall-Inman guided them around the island on their tour.
Paterson remembers Marshall-Inman as an incredibly patient man who, as he put it, politely put up with a barrage of questions and facts from his autistic son, who was obsessed with volcanoes and Māori culture.
"All during the tour, when we were on that island with Hayden, my youngest was just hammering him with facts and figures about volcanoes and Māori culture and he very politely put up with this non-stop barrage," Paterson said.
Paterson and his two sons, then aged 11 and 12, "had a ball" on the tour.
But even on the still day they visited Whakaari, Paterson said he could feel the immense, unpredictable power of the volcano as he stood in the same spot where visitors were pictured moments before Monday's eruption.
"Even on a good day, I remember thinking, if this thing decided to play games, that's it'," Paterson said.
"I can only imagine what it must've been like on Monday."
But the Australian trio's trip was not without its own drama. Their boat, the Pee Jay 5, burst into flames and sank on their return to the mainland.
The family, along with all aboard the alight ship, had to jump into the choppy seas without lifejackets to escape the blazing vessel.
Paterson remembers a chaotic scene of thick, choking smoke and inflatable boats speeding to save those jumping in the water.
He feared for his oldest son, who has asthma and his youngest, who couldn't swim well.
When a boat approached and gave Paterson a thumbs-up, he told his oldest son to jump in, where he was dragged aboard a waiting dinghy.
Paterson and his youngest son then leapt into the water.
"Because the seas were so rough, the boat was chopping up and down in the air. My [youngest] son hit the water and a wave pushed him under the boat," Paterson said.
He resurfaced, as Marshall-Inman sped over towards them in a rescue dinghy and dragged the 11-year-old aboard.
Paterson had drifted back towards the flaming Pee Jay 5, and Marshall-Inman came back for him.
"I'd inhaled a hell of a lot of smoke and I wasn't much good for anything."
Marshall-Inman grabbed him by the scruff of the neck and dragged him aboard.
"If it hadn't have been for him on the day, I dare say that my youngest would've drowned and that would've been the end of him - and I probably wasn't all that far off as well."
Paterson said he felt sick when he heard of the volcano's devastating eruption, and hoped Marshall-Inman would be returned to his family soon.
"I'm indebted to the lad after what he did that day," he said.
"He was incredibly nice to my little fella all day, he had the patience of a saint and then at the end of the day he rescued him."
Meanwhile, more than $200,000 has been donated to people and families affected by the White Island tragedy.
A Givealittle page for young guide Jake Milbank, who suffered burns to 80 percent of his body has raised more than $89,000.
A page for fellow guide Kelsey Waghorn, who also suffered terrible burns, has raised more than $57,000.
