Mr Miller said Faatafu denied threatening to chop off his son's head but had said he would give him a hiding if he ever stole a car again.
Judge Emma Smith asked why Faatafu hadn't been charged with endangering traffic, which carried a maximum sentence of 14 years.
Faatafu needed to know just how serious his actions were, said Judge Smith. Throwing an axe at a car could cause a fatal crash.
"You came that close to really injuring someone," she said.
She sentenced him to nine months supervision, including anger management, and 100 hours community work.