The crash happened when the southbound van deflected off a bank, crossed three lanes of highway and left the road soon after passing Tarawera, about 80km from Napier, about 6.45am on January 2, 2014.
It ended upside down and suspended above a ravine.
Driver Sandeep Kumar climbed out and made his way back up to the road, where he waved down another motorist.
The injured included a baby thrown out of the vehicle. While three people were seriously or critically injured, all survived.
Police later charged Kumar, who pleaded not guilty at a trial in Napier District Court in June. The outcome has been revealed in a reserved judgment by Judge Geoff Rea.
Kumar is due to appear in court again next Thursday for sentencing.
The court was told those in the van, including five from a Melbourne family, had left Auckland International Airport about 2am, bound for Hawke's Bay.
Kumar and another man had driven from Napier to Auckland the previous day.
On the return trip, Kumar, now 34, was said to have been awake for most of the journey but, having taken over the driving at Taupo, fell asleep at the wheel.
The judge said that fell below the standards of reasonable and prudent driving.
