Mr Skinner had opened his car door as he was reversing, Ms Johnson's report said.
"The evidence shows he was not wearing a seatbelt. Again this may have been to see better where he was going because there was very little room between the shelving unit and the normal path a vehicle would take entering or leaving the garage."
However, the open car door became entangled in a shelving unit, forcing the car to slide sideways and causing Mr Skinner to lose control. The car then hit another car parked in the garage.
"Mr Skinner then attempted to regain control of his car by continuing in reverse but steering it away from the parked car," the report said.
"However, by doing this, Mr Skinner was partially ejected sideways out from the driver's seat and the driver side of his car collided with the garage entrance wall. Mr Skinner was trapped and crushed between the garage entrance wall and the 'A' pillar of his car."
The police crash investigator found the primary cause of the crash was Mr Skinner losing control when his open door hit the shelving unit.
But Ms Johnson found the primary cause of Mr Skinner's fatal injuries to be that he was not wearing a seatbelt.
"Certainly, if the door had not been open, it would not have become entangled with the shelving unit and he would not have lost control," she said.
"But if he had been wearing a seatbelt, it is highly unlikely he would have been partially ejected, so would not have been trapped between car and wall, when the car collided with the garage entrance wall."
- APNZ