First responder Spady Te Pou said Mr Robertson was "bloody lucky".
"It didn't pierce an artery and it didn't hit any bone, so he was very lucky in that sense.
"He was still in a lot of pain, and the fish was still alive and he couldn't handle it, so he actually held on to the beak and pulled his leg out of it, but at the same time he dragged some of his calf muscle out too.
"One of his mates shoved it back in and wrapped a towel around it."
It took the group 45 minutes to get the boat back to shore, where fortunately there were two doctors at the bay on holiday who were able to immediately assist.
Mr Te Pou said "a bit of shock" hit Mr Robertson once the helicopter arrived, but he seemed in good spirits.
"He was still with it. When the boat came in I had a hacksaw, and he said, 'What have you got that for?' and I said I might need to cut somewhere to get it off.
"He said, 'You'd need more than a hacksaw to cut my leg off.'
"He was joking and laughing, everybody was making jokes, it was all good banter."
Despite the marlin's aggressive attempts to escape, Mr Te Pou said it still ended up second-best.
"One of our locals smoked it for him, and his mate said he plans to mount it as a trophy.
"He's a real tough character."
Later, at 8pm, Mr Dunham was called out in the helicopter again, this time to a farm.
A 52-year-old man helping a calf was attacked by its mother, which rammed him against a tree several times.
He suffered serious internal injuries, and was treated at the scene by St John paramedics before being flown to Tauranga Hospital.
Mr Dunham said it was one of the more unusual days he's had while flying the rescue helicopter.
"It's different, yeah. We do a few jobs with animals involved but not in the same day like this. It's been a different day all right."
He couldn't point to any cause for the rise in animal attacks. "Na, I think it's just sometimes shit happens with animals."
