New Zealand Rugby League CEO Alex Hayton confirmed a review of the Kiwis coaching staff and management will be undertaken next week following New Zealand's disappointing end to the tournament.
The victory marks Fiji's first-ever win against a tier-one nation and caps a miserable tournament for the Kiwis, who were booted from the quarter-finals a week after becoming the first top-three nation ever to lose to a second-tier side.
Fiji dominated the opening half but only had two points from a Apisai Koroisau penalty at the break.
They outscored the Kiwis by two penalties to one to equal the lowest scoring game in World Cup history.
Fiji nearly crossed in the fifth minute, but Brayden Wiliame lost the ball trying to get it down.
New Zealand, coming off a shock group-stage loss to Tonga that sent them to the tougher side of the draw, were lucky not to fall further behind early.
A Johnson penalty levelled the scores four minutes after the restart, Fiji storming back immediately with a sweeping move highlighted by a stunning run from Suliasi Vunivalu.
Fiji's defence, largely untested during an unbeaten pool run, was never really pressured in the first 40 minutes, the Kiwis their own worst enemies with a succession of handling errors and missed tackles.