"I literally came around a corner and saw this bloke down on the ground. The first thing I thought was one of our guys had bowled him for a six," he said.
"During that race, the road is absolute bedlam and that's a mongrel of a road at the best of times - there's no room, patchy cellphone coverage. Anything could happen. It was pretty obvious this guy was sick, though. At first I thought it was dehydration."
But Mr Gascoigne had had a stroke and his condition was rapidly deteriorating.
One of his fellow cyclists had managed to call for help on a mobile phone in one of Northland's notorious "black spots", but didn't know exactly where they were. Mr King called his boss Basil Richards on the his truck's Fleetlink radio to pass the GPS co-ordinates on to St John Ambulance. Then he went on his way.
"There wasn't much point in me hanging around. Help was on its way and the others cyclists were there with him," he said.
He had grabbed his first-aid kit as he jumped out of his cab. Although all the company's drivers had done first aid courses, and Mr King has been a professional driver for much of his working life, he said opening the kit was a first.
Stokes Transport manager Mr Richards was pleased his drivers were watching out for the public as the industry often had a bad rap because of the number of associated road incidents.