The bus suffered damage in the collision, which prevented it from stopping immediately at the scene, Mr Lynam said. It came to a halt a short distance away.
Nobody travelling on the bus was injured.
Meanwhile, the 4-year-old girl killed on Sunday's crash south of Taumarunui has been named as Kahui Matauwhati, of Masterton.
Her mother Ginnie Te Paea, who was thought to be driving the car when it crashed, said she would swap places with her girl "in a heartbeat" if she could. Kahui was described as "beautiful, cheeky, loving" and family members were "heartbroken".
"We wil b so lost witout u our Queen," her mother said. "R.I.P our darling girl."
Kahui died on Sunday afternoon when the car she was in left the road and flipped.
"They have crossed the centre line, hit a ditch on the other side of the road and the vehicle has rolled. Alcohol and speed were not factors," Sergeant Paul Dowie said on Sunday. "The parents were in a coherent condition, so they were aware of what had happened."
The girl's death had devastated the staff of her Masterton Kohanga Reo. Kahui was "the life of the Kohanga", Kathleen Albrett-Rimene told the Wairarapa Times-Age.
"She was a bright little girl who was top of the class, always asking questions."
Both parents were taken to Taumarunui Hospital but were released later that night.
The woman killed in a three-car crash in Southland on Sunday was a 56-year-old Chinese tourist, police said. They were working with Chinese authorities to notify next of kin.
