The summary of facts reveal the group had earlier that day driven from Auckland to Hot Water Beach where they spent the afternoon.
They weren't able to find anywhere to stay the night so headed south to Matamata.
As his passengers dosed on and off, De Costa used his front passenger's cellphone to navigate their way using Google maps.
About 7.35pm they were travelling on State Highway 2 at Netherton. The road was in complete darkness and surrounded by "extremely dense fog causing visibility in front to be around 50 metres".
De Costa came up behind a fuel tanker and was travelling at about 80km/h due to the poor visibility.
However, as they negotiated a right-curved section of SH2, De Costa began overtaking the truck, speeding in excess of 100km/h, crossing the centreline.
As he pulled out he saw lights from an oncoming BMW. In an attempt to avoid the crash he swerved to the right side of the road, however the front left side of the rental car collided with the front of the BMW, sending it rotating on impact before bursting into flames.
Growden-Olsen died at the scene.
De Costa's rental car became airborne and spun before coming to rest over an armco barrier, deep in a roadside ditch.
The passengers in the front seat, rear left and rear centre seats also died at the scene.
The speedometer of the tourist's rented Toyota was locked on just over 120km/h and the rev counter on nearly 6000rpm, giving police an indication of the speed on impact.
Nantillet suffered a plethora of serious injuries, including multiple fractures to his sternum, broken bones in his arm and leg, ruptured bowel, bruised spleen, cut liver and had part of his small and large intestine removed during three surgeries.
When questioned by police, De Costa was extremely remorseful and said the GPS told him he was on a straight piece of road.
He thought he could see a clear space in front of him that he could move into, checking to see the way was clear before beginning to overtake the truck.
