"I'm absolutely satisfied that this man has learnt his lesson ... the circumstances of this offence and the circumstances of the offender do not call for any form of custodial disposition in my opinion," he said.
But the Director of Public Prosecutions (DPP) contested the sentence in the Victorian Court of Appeal, arguing it wasn't harsh enough.
Supreme Court Chief Justice Marilyn Warren said the sentence was "manifestly inadequate" and described Judge Ryan's original comments as "inappropriate".
Abad met the 14-year-old at work - she was in the care of the Department of Human Services - after they shared a cigarette outside the Children's Court in July last year.
She told Abad she was 17, but police warned him that she was lying and actually underage. They told him if he had sex with her he would be committing an offence.
He broke off the relationship after the police warning but that same night, she came into his bedroom and got into bed with him. The pair had sex multiple times during their relationship, but it was this last encounter that Abad was charged over.
Justice Warren said: "The sentence was underpinned by observations as to the victim's presentation and behaviour, demonstrating that irrelevant matters contributed to the manifest inadequacy.
"The judge inappropriately and mistakenly took account of irrelevant matters, namely the attitude, demeanour, conduct and nubility of the victim and the effect she had on the respondent.
"I would observe that the observations made by the judge about the complainant and the descriptions applied were inappropriate, irrelevant and should not have been made."
The Victorian Court of Appeal said given the substantial age difference and the direct police warning, "the minimum sentence that ought to have been imposed was a community corrections order".
But the appeal was nevertheless dismissed, with the court finding the DPP was bound by its submission that the offending was at the "very low, if not lowest" end of the scale.
Judge Ryan isn't the first judge to be criticised for inappropriate comments in court.
Magistrate William Pierce drew gasps from a Sydney courtroom in June during the sentencing of Tinder troll Zane Alchin, after he appeared to sympathise with Alchin.
Last August, Alchin posted a series of comments on social media about a Sydney woman's Tinder bio, one of which was "the best thing about feminists is they don't get action, so when you rape them it's 100 times tighter".
Alchin pled guilty to using a carrier service to menace, harass and cause offence but avoided jail time, receiving a good behaviour bond.
The woman's friends launched a social media campaign against Mr Alchin and kept the case in the headlines.
Pierce described the response of the woman's friends to Mr Alchin as a "vast over-reaction" and said these comments had caused Mr Alchin "a great deal of pain which you didn't deserve".
Pierce compared the social media environment, and the response to Alchin's original comments, to a football match.
"My view is the closest analogy is a game of football," he said. "If you're on the football field you consent to a few bumps. You don't consent to being king hit with savage right hook that knocks you out for 10 minutes."
