Police got a rebuke in court for leaving three drunk men in a vehicle with the keys in the ignition.
Judge David Saunders told police it was a recipe for disaster.
"That was not proactive policing," the Greymouth District Court judge said, dismissing a drink-drive charge against Joshua Kelly.
"Four young men who had been drinking crowded into a ute ... To take the driver and not the keys is inviting more trouble on the roads."
Kelly, 20, of Ikamatua, was at the wheel of his ute at 11.05pm on May 5, when two policemen in a patrol car arrived after being directed there by another officer who had stopped the vehicle minutes earlier and was ferrying the driver back to the Greymouth police station for a breath test.