In a split decision watched by civil liberties groups, the Supreme Court of Canada ruled it would be unfair to allow the adjudicator's decision to bar Wayne Penner from pressing his lawsuit.
"I brought this case because I have always felt that police should be accountable for their actions, and that judges — not police adjudicators — have the responsibility to hold police accountable," Penner said in a statement.
"The Supreme Court of Canada agreed with us — it is a good day for justice."
The case arose in January 2003, when Penner lodged a complaint against two officers with Niagara regional police after they arrested him for making chirping noises and other disruptive behaviour in a courtroom in St. Catharines, Ont.
Penner alleged misconduct under the Police Services Act. He also sued for damages.
At a disciplinary hearing in 2004, an adjudicator appointed by the chief of police dismissed Penner's complaint against the officers.
Penner appealed to the Ontario Civilian Commission on Police Services, which overturned the decision on the grounds the officers had no authority to arrest him in the courtroom.
On appeal, Divisional Court restored the adjudicator's decision which absolved the officers after finding the commission's ruling unreasonable.
Armed with the Divisional Court decision, police argued Penner should not be allowed to sue them. The Ontario Court of Appeal agreed.
In his appeal to the Supreme Court, Penner maintained it would be wrong to allow the police disciplinary process to shield officers from a civil action.
In its 4-3 decision Friday, the high court agreed, saying it would be a "serious affront to basic principles of fairness" to allow that to happen.
"Potential complainants may not come forward with public complaints in order to avoid prejudicing their civil actions," the court said.
In dissenting, three of the seven justices noted the doctrine of finality in legal proceedings
"(Penner) should not be allowed to circumvent the clear findings of the hearing officer and put the parties through a duplicative proceeding, which would inevitably yield the same result," the dissenters said.
Julian Falconer, Penner's Toronto-based lawyer, said the decision means people can access the police-complaints system without fear the result could be used against them in a civil suit.
"The police complaints system was intended to protect the public against police abuse," Falconer said.
"It was never intended to be used by the police to gain a tactical advantage in civil proceedings."