Colin Webster was convicted of behaving in a disorderly manner and assaulting a police officer in the execution of duty but after an appeal both convictions were dropped.
Justice Matthew Palmer made the judgment on Webster's appeal today in the High Court of New Zealand, finding a miscarriage of justice took place.
In August 2008, Webster called police for assistance at his Manurewa home because of an altercation with his methamphetamine-addicted son.
"Webster was highly agitated and holding a metal pole a short distance from his son when the Police arrived," Palmer's summary said.
"The two constables did not know quite what the situation was.