But Justice John Little said the officer's driving wasn't illegal.
He said he had reasonable doubt in the case against Const. Chris Luimes and so acquitted him on a charge of dangerous driving causing death.
"While the collision was a tragic event and took the life of one driver and left Const. Luimes permanently disabled, his driving was not a criminal act," the judge said Friday.
Luimes, 37, refused to talk to reporters as he walked out of the courthouse with about a dozen fellow officers.
Court heard that he was part of a surveillance team assigned to follow a suspected gold thief on the morning of March 8, 2012. He was in plain clothes and driving an unmarked car with its lights and siren off.
Another officer was driving behind the suspect and Luimes was trying to keep up with them as he sped through a southside intersection at 117 km/h, nearly double the posted speed limit.
His car then struck an oncoming vehicle that was making a left-hand turn.
Anne Walden was pronounced dead at the scene.
Luimes testified during his trial that he has no memory of the crash or the moment leading up to it. Court heard he broke a leg and two vertebrae and will never be able to run again. He now works as a police dispatcher.
The judge said expert evidence showed that Luimes did hit his brakes and tried to avoid the collision. But if he been driving the speed limit, or just slightly over, the crash would have been a fender-bender and no one would have been hurt.
Little pointed out that police are allowed to speed while on duty. Between 2012 and 2014, 41 cases were recorded of city officers driving 50 km/h over posted limits. Investigations showed they were all justified.
Defence lawyer Mike Danyluik argued during the trial that the weather was clear the day of the crash and there was light traffic. Speeding alone isn't dangerous driving, he said.
Crown prosecutor Jonathan Hak told court there was no reason for Luimes to race through the intersection. Some officers even testified that the world wasn't going to end if they lost the suspect.
Several other drivers testified they were surprised by how fast Luimes was driving. One said that at the time he thought Luimes must be an "idiot."
Three said they also saw Walden's car and hoped she wouldn't make the turn.