At about 1am, Officer A was "patrolling" in his police car in Hastings when responding to an incident, Officer A started driving with his emergency lights on.
As he was driving, he saw a car travelling in the opposite direction, which he thought matched the description of the stolen Mercedes.
The Mercedes stopped when lights flashed behind it, and Officer A parked about five to 10 metres behind it, slightly out to the right-hand side.
He armed himself with his Glock pistol, removing it from a locked box by the front passenger seat.
At about the same time the driver of the Mercedes, "Mr X", got out of his car.
Officer A got out of the Police car holding his pistol and stood behind the open driver's side door. Mr X was standing on the road. There are conflicting accounts as to whether Officer A was pointing his pistol at Mr X, or at the ground.
Officer A, as well as other officers who arrived shortly after, spoke with Mr X on the footpath beside the road. Police searched Mr X's car but did not find any firearms. Police established that it was not the stolen Mercedes they were searching for. An inspector arrived and spoke to Mr X, at which point he was allowed to leave.
Officer A subsequently served Mr X with an infringement notice alleging that Mr X had committed three traffic offences while driving the Mercedes.
Despite the incident leaving the driver shaken, no victim support assistance was offered - something which he also complained about. The IPCA, however, ruled that the incident was not one that would have led to such an offer.
Authority Chairman, Judge Colin Doherty said: "the authority accepts that any incident in which a firearm is drawn in the presence of a member of the public, whether aimed or not, would likely be distressing for that person".
Eastern District Commander, Superintendent Tania Kura said police agreed with the IPCA's decision that the officer's actions were appropriate and reasonable given the circumstances.
"I'd like to acknowledge the officer and his colleagues for their work that night.
"While on his way to another job, the officer observed a vehicle that closely matched the description of a car that had been stolen along with 10 firearms.
"As noted by the IPCA, the officer reasonably formed the belief that an incident involving the driver of the vehicle could be life-threatening, given the potential presence of a number of firearms.
"The officer astutely assessed the potential risks involved in stopping the vehicle and took the appropriate steps to protect himself and others from potentially serious harm."