The drama unfolded on Wednesday afternoon as the two men headed home from work in separate cars along the remote Tapu-Coroglen Rd, north of Thames.
Mr Veal came across the accident about 4.20pm when he, partner Sammi-Jo Timm and uncle Peter Dehar were flagged down by a relative about 2km from the Thames Coast Rd turnoff.
He found Mr Jenkins salvaging work gear from his mangled van.
"I immediately jumped down the bank to see if he was all right and he had a few cuts and a sore shoulder, so we thought, 'Oh sweet'. I just gave him a hand over the creek and got him into the car and we were going to take him to A&E in Thames."
But minutes into the trip, they had to pull over so Mr Jenkins could be sick. Moments later and without warning, he had a seizure.
"His face went the darkest blue I've ever seen," Mr Veal told the Weekend Herald. "Blood was coming out his eye. He was in such a state that you could hear his teeth grinding."
Ms Timm went to call 111 while Mr Veal and Mr Dehar laid Mr Jenkins on the ground and began CPR.
"You couldn't give him mouth-to-mouth 'cos he was just frothing and grinding," Mr Veal said. "It was full on. I've seen some seizures, but that was top 10.
"Seeing blood come out his eye was pretty gruesome. It was a lot of pressure. I've never actually been in those circumstances before."
Mr Veal said his uncle remained calm, telling him to slow the compressions while he continually checked to make sure Mr Jenkins did not swallow his tongue.
Fearing he was going to die, the two men worked on.
After 10 minutes and as Mr Jenkins came to, fire and ambulance crews arrived.
Mr Jenkins, who had a "mean lump" on the back of his head, was flown to Waikato Hospital and assessed by the neurosurgical team.
Mr Veal, a father of three who learned CPR on the job when working as an arborist, said he was "pretty stoked" with the success of his and Mr Dehar's efforts because he feared Mr Jenkins was seconds from death. "I honestly reckon he'd have died."
He described Mr Jenkins as a good worker who was popular among the forestry crew.
"He's a choice guy. Honest. Always smiling, even on the baddest days. He's awesome."
Yesterday, Mr Jenkins was transferred to Thames Hospital, where he was in a stable condition.
Mr Veal was looking forward to seeing his mate.
"I'll go and give him a big cuddle and tell him don't ever do it again, because I really don't want to do that again. Especially with one of your bros."
Waikato district road policing chief Inspector Freda Grace said if it hadn't been for the quick actions of those first on the scene, Mr Jenkins might have died.
She said police would recognise their heroic action.
• Want to learn CPR? Many places offer courses. You can find out where from St John, 0800 FIRST AID.
