Adelaide Archbishop Philip Wilson is "disappointed" at being found guilty of concealing child sexual abuse but others are "delighted" at his conviction.
New South Wales Magistrate Robert Stone handed down the verdict against the high-ranking Catholic official in Newcastle Local Court today following a magistrate-only trial.
The 67-year-old clergyman was accused of covering up the abuse of four boys by pedophile priest James Fletcher during the 1970s in the NSW Hunter region.
Former NSW Police Detective Chief Inspector Peter Fox, who had previously alleged the church covered up Fletcher's offending, said he was "delighted" because now someone within the church was being held to account.
"It's a major turning point. It's been very difficult for so many of these witnesses, I can't tell you how difficult it's been," Mr Fox told AAP.
"I am confident this will make waves in the Vatican."
The former policeman, who was with the abuse survivors and their families when the verdict was revealed, said some of those involved were sombre because the news hadn't sunk in.
"Their stomachs have been churning," he said.
Mr Fox also said the abuse of one of the survivors could have been entirely prevented had Wilson taken action when he was told of Fletcher's abuse of then-altar boy Peter Creigh who gave evidence at the trial.
Archbishop Wilson is now considering the reasons for the magistrate's ruling.
"I am obviously disappointed at the decision published today," he said.
"I will now have to consider the reasons and consult closely with my lawyers to determine the next steps."
He is the most senior Catholic official in the world to be charged and convicted of such a charge, of concealing a serious indictable offence of another person.
