A paedophile football coach has complained of alleged "judicial copying" as he challenges the length of his 20-year jail sentence.
Lawyers for Stephen James Porter, 52, filed submissions in the ACT Court of Appeal this week in their bid to reduce his prison term, which includes a 12-and-a-half-year non-parole period.
Justice Chrissa Loukas-Karlsson imposed the sentence in the ACT Supreme Court last year after Porter pleaded guilty to serious charges that included maintaining a sexual relationship with a child.
Porter, formerly of Macgregor, also admitted grooming, using a child to produce exploitation material, and possessing such material.
The most serious of Porter's crimes involved the sustained sexual abuse of a boy he met while coaching junior Australian rules players at the Ainslie Football Club.
Porter did not coach the boy's teams but abused him between 2015 and 2018 during one-on-one training.
A central issue in his case was a dispute over the number of occasions on which Porter exploited the boy.
He conceded this had happened about 14 or 15 times, but the victim said the true number of occasions was between 35 and 45.
Justice Loukas-Karlsson, who presided over a disputed facts hearing, accepted the victim's evidence and sentenced Porter on the basis there had been 35 incidents.
In his appeal submissions, written by two barristers and filed by solicitor Adrian McKenna, Porter argues the evidence did not permit Justice Loukas-Karlsson to find that number beyond reasonable doubt.
Porter's appeal barristers, Tim Game SC and Riyad El-Choufani, also claim a "substantial portion" of the judge's reasons for that conclusion were "copied, almost verbatim", from the prosecution's submissions.
"The disputed facts hearing miscarried," Porter's lawyers claim.
"In particular, the extent and manner of judicial copying rendered the sentencing judge's reasons inadequate because they did not expose how the judge independently arrived at her conclusions."
After conducting what they described as "a careful comparison" of the disputed facts judgement and the prosecution's submissions, Porter's lawyers claimed the judge appeared to "uncritically accept" the latter.
"On occasions where she expressly adopted a [prosecution] contention, her honour pithily stated her agreement without further explanation or independent analysis," Mr Game and Mr El-Choufani wrote.
Porter's third and final ground of appeal alleges the portion of the sentence related to the grooming offence, which involved a different Ainslie Football Club player, was "manifestly excessive".
Prosecutors are due to file their response to the appeal later this month.
Should Porter's appeal succeed, his lawyers have outlined different options available to the appeal court.
These include re-sentencing Porter or, depending on which ground is upheld, remitting the matter to the Supreme Court for re-hearing by a different judge.
If Porter's appeal fails, he will not become eligible for parole until May 2034.
The appeal hearing has been listed for May 16.