"If you lent a firearm to an unlicensed or intoxicated person, you would expect repercussions for anything they did with it, and a car is no different. A motor vehicle in the wrong hands is just as deadly," he said.
Aiding and abetting carries the same penalty as the original driver's offence, including mandatory disqualification, said Mr Newton.
Beazley had been out celebrating the 18th birthday of Mr Alderson on May 25 last year.
They'd been kicked out of a pub because they were intoxicated, bought more booze and drove around drinking, before getting dropped off by their sober driver at another pub near Beazley's home in Opawa, Christchurch.
The drunken pair then decided to drive from there to Rangiora, about 25km away.
Beazley said he was too drunk to drive but Mr Alderson, who only had a learner's licence, made the fatal decision to get behind the wheel of his friend's car.
Shortly afterwards, around 1.45am, he was killed when he lost control of the vehicle, which spun into a power pole.
Today Beazley pleaded guilty to the charge of allowing Mr Alderson to drive on Flaxton Rd, near Rangiora, a charge that will potentially set a legal precedent.
He had originally pleaded not guilty, but changed his plea this morning ahead of a scheduled hearing before Judge Christopher Somerville.
Mr Alderson died at the scene, while Beazley - who was the only one wearing a seatbelt - was hospitalised with neck and shoulderblade injuries.
He later told police he let his younger friend drive because he was quite drunk and didn't drive while under the influence.
He also claimed that he thought Mr Alderson was on a restricted licence, not a learner's.
Beazley has been remanded on bail to July 5 for sentencing, with Judge Somerville ordering a pre-sentence report to include reports on his suitability for community or home detention.
He also asked for a report on emotional harm reparation.
Beazley made no comment as he left court today.
