Melbourne, Australia (CNN) Cardinal George Pell will remain behind bars while an Australian appeals court considers whether to overturn his conviction on five charges of sexually assaulting two choirboys in the 1990s.

A jury unanimously found Pell, 77, guilty of all charges after a secret five-week trial last year, and in March he was sentenced to six years in prison, with a non-parole period of three years and eight months.

On Thursday, prosecutor Christopher Boyce QC presented the crown's argument that it was possible for Pell to commit the crime in the manner, time and place described by the choirboy or complainant, who is now aged in his 30s.

It followed a day of testimony Wednesday from Pell's barrister, Bret Walker SC, who presented 13 reasons why there should have been reasonable doubt in the minds of jurors when they returned the five guilty verdicts.

Pell sat to the side of the court, dressed in black with his clerical collar, taking notes on the day's proceedings, which commentator David Marr described as a "trainwreck."

"The crown's barrister, again and again, was simply lost for words," said Marr, author of The Prince: Faith, Abuse and George Pell, who was in court for the two-day hearing.

"That was not an impressive performance, but mind you, we couldn't see the documents, we couldn't see what was being quizzed backwards and forwards between the bench and the bar table. We couldn't tell whether that barrister was actually landing it in the end, but we could see that it was agony getting there -- and why?"

Boyce's arguments were broadcast via a livestream on the Supreme Court website, which at one stage was muted when he accidentally revealed the name of the complainant. Under Australian law, victims of child abuse cannot be named.

"It was a very stressful and agitating day," said a survivor of child sex abuse who goes by the name of Michael Advocate.

"We're being infuriated by Pell's arrogance in the clothes that he was wearing because he's a criminal, we've got incompetent counsel who are naming the victim, which everyone knows is a criminal offense, no wonder it's a disastrous day for us."

The second choirboy involved died a few years ago from an accidental heroin overdose without ever speaking about the attack.

Boyce began Thursday's proceedings by telling the panel of three judges that "the complainant was a very compelling witness." In its written submission, the crown said his ability to recall the layout and wood paneling in the priests' sacristy where the attack took place spoke to his "truthfulness and reliability."

In court, Boyce pointed to conflicting evidence given by the complainant and witness Monsignor Charles Portelli, who testified that he always accompanied Pell during and after the mass, so wouldn't have been left alone to commit the crime. Boyce suggested the jury came to its verdict of guilty beyond reasonable doubt because they accepted the complainant's testimony was more believable than Portelli's.

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Pell's defense

In his response, Pell's barrister, Walker, said Portelli's evidence was sound, given he was being asked to recollect the events of 22 years ago, as was everyone involved in what have been a difficult case.

In its submission, Pell's legal team elaborated on 13 "solid obstacles" that it said stood in the way of a guilty verdict. They included that it was not possible for Pell have to been alone in the priest's sacristy, for no-one to have noticed the choirboys were missing, and for the attack not to have been seen or heard by anyone milling around outside the room.

Walker suggested the jury discounted evidence from Portelli and other witnesses about the regimented nature of the occasion, and claimed that Pell, being new to the position of Archbishop, had made a point of meeting congregants outside the Cathedral's western entrance after mass.

"If he was at the western door during that time, then the law of physics tells us this is literally, logically impossible, for the offending to have occurred," Walker told the panel of three senior appeal judges.

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Fall from prominence

Once a close adviser to Pope Francis , Cardinal Pell returned from the Vatican to Australia to contest the charges, which he has strenuously denied and dismissed as a "product of fantasy."

The jury returned the guilty verdict last year, but the result was kept secret until February to avoid prejudicing another, separate trial, which was abandoned by the prosecution after the judge refused to admit some evidence.

As soon as the prosecution pulled the charges, the judge lifted the suppression order and out split weeks of evidence painting the cardinal as an arrogant "madman," who seized the opportunity to attack two boys so bound by their faith to the Church and his authority, they would never dare tell anyone about their ordeal.

As he handed down his sentence in March, Judge Peter Kidd told the court that "the offending which the jury has found you have engaged in, was on any view, breathtakingly arrogant."

Pell's supporters branded his conviction as a travesty of justice carried out by a jury who were seeking to pin the blame for the Catholic Church's failings on the shoulders of a man who had in fact been working hard to help victims of Church abuse.

At Pell's sentencing hearing, high-profile friends, including former Australian Prime Minister John Howard, wrote character references describing him as a person of "exemplary character."

The cardinal's fate now rests with three of Australia's most senior appeals judges: Chief Justice of Victoria's Supreme Court, Anne Ferguson, President of the Court of Appeal, Chris Maxwell and Mark Weinberg. Only two of the three need to agree on the ruling, which they're expected to explain in a detailed document. The court is expected to set a date for their verdict in the coming weeks.

If Pell's conviction is overturned, the prosecution could take its case to the High Court. Pell could do the same if he loses. The High Court may or may not agree to review the case, but if it does, its decision is final.