"The victim was then thrown over the roof of the vehicle before landing on the road surface."
The victim suffered a broken femur, a smashed hip, two fractured vertebrae in his lower back, and had to have surgery that night.
He spent two weeks in Hutt Hospital and faces months of rehabilitation.
Peter's lawyer said Peter found himself in court "though an act of carelessness".
He said Peter had an "exemplary career and life", was a "devout man of the church" and a family man.
Judge Craig Thompson convicted Peter and ordered him to pay emotional harm reparation to the victim of $2000, and disqualified him from driving for six months.