The impact ripped the wing mirror off the truck and left him with severe injuries - including a smashed pelvis, compound fracture to his right femur and bowel perforation.
The couple, who have lived in the United Arab Emirates for nine years but are from Wellington, said if they hadn't been talking on the phone when Nick was struck he'd likely have died there - on an isolated part of Highway 40 because it would've been hours before anyone found him.
Sarah - who was holidaying in Cyprus with the two youngest of their four daughters - said she'd called him to check in about 8.10am local time.
They'd often talk hands free on Skype while Nick was running - his phone strapped to his Camelback waterbag which was slung over his body, Sarah would see his feet moving in the video and occasionally catch a glimpse of his face. They could hear each other using speakerphone.
That morning they were talking about how Nick planned to have breakfast with their eldest daughter, 24-year-old Emily, and her friend Kieran Bullock, who were following his journey in a motorhome, in a couple hours.
Then the ute hit him - and the phone went flying through the air.
"It was like the movies. I saw just the rolling of the grass," she said.
"I was like 'what's happening'. It went silent and then he yelled. When I heard that yell I knew that something was seriously wrong."
The phone had been landed a few metres away from Nick so she couldn't see him but heard him say he'd been hit by a vehicle and was lying a ditch.
A nurse who trained in the emergency service response unit while living in the Hawke's Bay, Sarah knew she had to stay calm and started an assessment, questioning Nick about his injuries.
"I tried to get up on to the road side because nobody could see me but I couldn't because my pelvis had been smashed and my right leg was in a real mess too," Nick said.
She stayed on the line with him and also called Emily to explain what had happened and told her to call 911.
Four state troopers were sent out to look for Nick, who had started to drift in and out of consciousness.
"I could hear how laboured his breathing was," Sarah said.
"I'd yell at him to stay with me. That was a bit scary because that was when I thought he could die."
While help was on the way, Sarah urged him to tie a shirt around his right leg which was bleeding profusely. But due to his injuries he couldn't.
Then the call cut out.
Minutes later the troopers found him and called in a helicopter.
He was flown to hospital in a critical condition and rushed straight into surgery.
Within three hours Sarah was on plane to the US and 35 hours later was reunited with her husband at his beside.
During the month since the incident Nick had five major surgeries and is now facing months of rehabilitation before he can walk on his own again.
But the couple considered him to be fortunate.
"He's very, very lucky he doesn't have a serious head injury," said Sarah.
Although doctors have told Nick he will most likely be unable to run again - the 53-year-old is determined to prove them wrong and finish the last 922km left of his run.
"I don't know when that will be but I'd certainly like to do it with a few close friends," he said.
First though he would have to take "baby steps".
Nick's medical bills had already totalled more than $500,000 and would increase during his rehabilitation.
Although he had insurance it was unclear how much would be covered because the insurance company would only confirm what it would pay out once he'd been discharged from hospital and knew the final total, Sarah said.
"For me that's one of the hardest things, is not knowing the bigger picture of what this will cost us a family. We just don't know at this stage."
A relative had set up a Give a Little page to raise money for Nick's ongoing treatment.
Police are yet to arrest anyone in relation to the hit and run, but say they believe the vehicle involved was a 1992 to 1998 dark-coloured Chevrolet or GMC ute.
Nick appealed for the driver to turn themselves in.
"It's really, really important that this individual is kept off the road because the next individual that it happens to might not be so lucky."
Anyone wanting to contribute to Nick's recovery can make a donation via Give A Little by going to: https://givealittle.co.nz/cause/gettingnickbackonhisfeet