A former violin teacher from Chatham-Kent, Ont. is going back to court again after an appeal panel ruled the trial judge "erred in law."

Last year, Claude Trachy was acquitted of 51 sexual assault-related charges, shocking former students. The decision was then appealed in May. Some of those acquittals have been set aside.

The appeal decision, released Tuesday, said the trial judge "erred in law" by acquitting Trachy on the sexual assault and indecent assault charges, ruling that they had been proven beyond a reasonable doubt.

During the trial, female students testified that in the 1970s and 80s, Trachy had touched their breasts, had them remove their blouses and bras and play with their breasts left exposed. In some instances, the former students testified plastic moulds had been taken of their breasts.

According to Trachy, his actions were to measure students to fit them for violin shoulder rests and were not for a sexual purpose. Justice Thomas Carey at the time accepted Trachy's explanation, ruling in his favour.

Crown attorney John Patton, on appeal, argued that Carey's decision "brushed over" major evidence and did not consider the suffering of the complainants.

As a result, the acquittals on some charges have been set aside. Stays have been entered on two counts, due to the age of the claimants at the time. Acquittals on sexual exploitation and sexual interference charges will stand.

"There was a quite a bit of joy," said one of Trachy's victims. "A whole pile of emotions at once. It's been a long four years since the investigation began."

The victim, who can't be named due to a publication ban, spoke to CBC News from her home in Chatham.

"Being heard was just what we needed," she said. "We've all become stronger women because of it."

The woman said she'd like to see more instruction given to judges on how to deal with sexual assault victims.

"In the end, if there had been a new trial, we would have all had to tell our stories again. Nothing would have been new, we were all credible witnesses," she said. "That would have been a difficult thing for us to do. We need closure and we need it quickly."

The three-judge appeal panel included Justice Mary Lou Benotto, Justice Grant Huscroft and Justice David Doherty, who issued convictions on 25 charges related to 18 complainants.

The appeal panel has remitted the matter back to Superior Court and requested a different trial court judge determine sentencing.

"The end is in sight," said the victim. "All along I have gone through some healing. I look forward to being able to put it behind me, and move on."

CBC News reached out to Trachy's lawyer Matthew Gourlay, who did not respond to a request for an interview.