Higginson was driving Bartlett to Auckland when he failed to take a bend on State Highway 3, near the intersection of Mangakowhai Rd, south of Piopio on December 30, 2019.
He crossed the centre line, crashing into an oncoming vehicle being driven by a local 53-year-old woman.
She suffered serious leg injuries in the crash, and Bartlett died.
Higginson was found to have had a cocktail of drugs in his system, including MDMA, cannabis and methamphetamine, at the time of the crash.
However, a police crash report indicated that fatigue was likely a key factor, it was heard at the sentencing.
At today's court appearance, Higginson pleaded guilty to the charge of possession of cannabis.
The charge stemmed from a police search of his Bell Block address on May 4 this year.
During the scout of the property, officers came across a "large quantity" of cannabis plants in a grow room in the garage, and more stored in containers inside the home.
While Higginson's flatmate took responsibility for what was discovered, Higginson confessed to officers that he had his own stash of the class C drug.
He had 129g of cannabis head stored in glass jars in his bedroom.
In explanation, Higginson told police he has a medicinal cannabis card but said he couldn't afford to buy the drug on prescription.
Defence lawyer Julian Hannam said the case was one of "a decreasing number of cannabis prosecutions".
He argued the best outcome was by way of an order to come up for sentence if called on.
While prosecutor McKenzie didn't "necessarily" oppose, he pointed out Higginson was currently serving a sentence for causing death while driving under the influence of drugs.
Judge Paul Keller said it was a large volume of cannabis found on Higginson.
But because he had no prior relevant convictions, he was young, employed, and complying with a "long" term of home detention, the judge adopted the defence's proposed sentence.
Higginson was convicted on the charge and ordered to come up for sentence if called on.
His flatmate was also charged in relation to the cannabis found and is currently before the court.