"[It] again highlights the danger of driving while alcohol intoxicated and under the influence of cannabis such that it may have affected the ability of the driver to control his motorcar."
The three men were driving north on Eastern Hutt Rd, Wellington, on December 11, 2008 when the smash happened about 7.10pm.
Police estimate Mr Gregor was doing between 112km/h and 118km/h in an 80 km/h zone when he overtook another car.
When he came to a slight to moderate right-hand bend, he lost control as the car began to fishtail.
The car hit a crash barrier, spun, and left the road before rolling and crashing into a concrete power pole, which snapped at ground level and wrapped itself around the car.
A witness was driving in the opposite direction at the time when she saw two cars coming towards her - the first a "boy-racer type car" with a large exhaust pipe.
She saw Mr Gregor's car fishtail three times before flipping over and hitting the power pole.
The woman stopped her car, grabbed a first aid kit, and crossed the road to the crash scene.
A post-mortem examination on Mr Gregor's body was completed on December 12, 2008 and found he died of blunt force injuries to the head and chest.
Forensic pathologist Dr John Rutherford commented that the toxicology tests revealed the presence of alcohol and cannabis which would have been "sufficient to cause impairment of judgement and/or coordination".
Mr Mehlhopt, who survived the crash but later died in Wellington Hospital, died of multiple intracranial haematomas, the coroner concluded.
