The Edmonton teacher fired nearly three years ago for giving students zeros has been cleared of charges of unprofessional conduct.

The charges stemmed from an episode dating back to 2012, when Lynden Dorval was suspended and later fired after violating Ross Sheppard High School’s “no-zero” policy by giving students zeros when they failed to hand in assignments or missed tests.

On Friday, the Alberta Teachers’ Association cleared Dorval of three charges of unprofessional conduct related to the incident.

Earlier this year, the Alberta appeal board also ruled Dorval had been unfairly treated. Ross Sheppard’s “no-zero” policy, which was designed to protect students’ self-esteem, has also been reversed since Dorval’s firing.

But for Dorval, the advances are bittersweet. In the years after his suspension, the former physics teacher retired early and is no longer teaching.

“Everybody has said that everything was wrongly done in terms of accusations, so then why aren’t I still teaching in a classroom right now?” he said.

Dorval also questioned whether the association’s hearings should have gone forward in the first place.

“I’m obviously happy that I was found not guilty, but still disturbed that my own union would do this to me.”

The Alberta Teachers Association said it was their responsibility to investigate allegations.

“The association received a complaint of unprofessional conduct against Mr. Dorval, and the association was obligated to investigate that complaint,” said Jonathan Teghtmeyer from the Alberta Teachers’ Association.

The association’s executive council has 30 days to appeal Friday’s decision.

With files from CTV Edmonton’s David Ewasuk