"That morning as he walked to the car he turned and gave us a smile and a wave," said Batchelor.
"That was the last time we saw him."
He was near Whakamarama, just 20 minutes' drive from his brother's place, when his rental car crossed the centre line and collided with a vehicle driving in the opposite direction.
The stretch of road is among the most deadly during the Christmas road toll period, a Herald investigation shows.
Coroner Wallace Bain ruled Keane either fell asleep at the wheel or had a heart attack while he was driving.
He died at the scene.
"I had a call from my uncle to see if I had heard from dad. He heard that there had been an accident," said Batchelor.
"I tried to call dad but it was just going to answer phone. In the meantime, my uncle managed to get hold of the police and and he had to ring me and tell me.
"It was shocking. We had lost another family member a couple of weeks beforehand so it was quite fresh.
"You are just in a state of disbelief, especially having only seen him that morning and knowing he was a very efficient driver."
It was still hard to comprehend, she said.
"It's different to losing someone for medical causes that may take a long time to pass away, you still have the same grief but you're also suddenly dealing with the police, the coroner and other people involved.
"Always tell your loved ones you love them because you never know when it's going to be the last time."
The series
Day 1: Our holiday blackspots: A Herald investigation reveals the most dangerous places during the Christmas Holiday road toll
Day 2: What's behind the horror on our roads? A look into the factors that are causing crashes.
Day 3: Picking up the pieces: Meet the people on the front line who face grisly scenes every day to save crash victims.
Day 4:The case for a lower road toll: Experts pitch ideas they think would save lives