When that driver returned a few minutes later Mr Rihari had been struck by another vehicle.
Oruru Road has neither lighting nor a footpath. Miss Hartigan was walking on the left-hand side of the road when she was struck.
Senior Constable Warren Bunn, of the police Serious Crash Unit, said no one would be prosecuted over the deaths, adding that the fatalities were tragic for the victims' families, but also traumatic for the drivers.
While it was well known that drinking and driving didn't mix, drinking then walking home on rural roads with high-speed traffic, especially where there were no footpaths or streetlights, was also risky, he said.
He urged Northlanders to have a plan for getting home safely after going out at night.