Dr Retford's husband, Darren Retford, said his wife left home just before 6am and was driving along the same 100km/h stretch of road she travelled on every morning.
He received a "terrifying" phone call from her minutes later.
"About 6.08am I got a phone call from her saying she had been in an accident and that she's okay but the other guy didn't have a pulse."
Emergency services arrived at the accident - near Whitford's Zen Gardens - to find the man had died.
A St John spokesman said Dr Retford was initially assessed as having serious injuries, but that was downgraded to minor before she was taken to Middlemore Hospital.
Mr Retford said his wife was driving away from Beachlands and was near a bend when she saw headlights coming towards her.
"She just saw two lights coming to her and thought, 'He's on my side of the road, what's going on?' The next moment she thought, 'I'm going to die' and after that, nothing."
The family, who have two sons and a daughter aged 7, 6 and 2, had upgraded their vehicle from a Volkswagen stationwagon at Christmas time. "I think if she was in her old car she wouldn't be here today."
Police want to hear from anyone who may have seen the two vehicles involved at any time prior to the crash, on the Whitford-Maraetai Road or surrounds.
"The cause of the crash has not yet been determined, but we will be considering speed and alcohol as possible factors," said Constable Amy Weston.
"Our thoughts are with the family of Mr Huxtable at this difficult time."
Anyone who may be able to assist with information about the crash is asked to contact Constable Weston on 09 215 6118. Information can be provided anonymously to the organisation Crimestoppers on 0800 555 111.
