On Monday, April 15, the Federal Court's Justice Michael Lee is set to hand down his highly anticipated decision in the defamation case brought forward by Bruce Lehrmann against the network that reported the allegation.

The judge is expected to make several key findings about and surrounding the alleged incident.

But Justice Lee's decision is unlikely to be black and white, conclusively resolve the infamous case, entirely favour one side, or go unchallenged.

He has spent months working on a colossal and unenviable task, which involves decisions about identity, truth, qualified privilege, witness credibility and more.

You may have, like tens of thousands of Australians, watched proceedings on the YouTube live stream.

But if you need a refresher on what happened in November and December of last year, here is the key evidence heard in the Bruce Lehrmann v Lisa Wilkinson and Network Ten defamation trial.

"Tonight, claims of rape, roadblocks to a police investigation and a young woman forced to choose between her career and the pursuit of justice," Ms Wilkinson told 725,000 Australians on February 15, 2021.

"And it all happened right in the heart of our democracy."

The Project's Monday night program aired Brittany Higgins' allegation of being raped inside a ministerial office two years earlier. It did not name the accused "senior male colleague".

Despite this, Mr Lehrmann claimed being identified as the alleged perpetrator and, in turn, being viewed as "probably one of the more revolting predators of the recent history of this country".

"My client has been publicly maligned, as certainly the most prominent rapist," barrister Matthew Richardson SC told the court in November.

As a result, the former Liberal staffer turned law student sued Ms Wilkinson and Ten for defamation, leading to last year's month-long civil trial.

In his statement of claim, Mr Lehrmann alleged the program made several defamatory imputations against him.

Those imputations were that he raped Ms Higgins, continued assaulting her when she awoke, crushed and bruised her leg, and left her "in a state of undress" after the fact.

In their defence, the journalist and broadcaster aimed to prove the allegation was substantially true and, if that failed, that they had at least reported it reasonably.

Mr Lehrmann has always denied raping Ms Higgins on a ministerial office couch in the early hours of March 23, 2019, when the pair worked for Senator Linda Reynolds.

If he finds Ten identified Mr Lehrmann in the program, Justice Lee must then decide, on the balance of probabilities, if the assault occurred. That is, is it more likely than not it happened?

The answer to that question, among many others, could see Mr Lehrmann forced to pay millions in legal costs, be owed compensation of some kind, or several possibilities in between.

If the truth defence fails, the judge must then assess Ten's professionalism in producing and publishing the story.

A number of other factors could also affect the possible awarding of damages to Mr Lehrmann, including his credit and honesty as a witness, and Ten's behaviour since The Project broadcast.

Justice Lee can also find that sex took place on the morning in question but that it was consensual, bringing in an abuse of process question.

Even if found to be defamed, Mr Lehrmann could walk away with nothing.

The judge has already flagged "real credit issues" for both Mr Lehrmann and Ms Higgins. Lies and faded memories under cross-examination became catnip for barristers and media headlines alike during the trial.

Witness credibility would become one of the major reasons why Ten was allowed to reopen its case at the 11th hour and a judgment was delayed.

Mr Lehrmann's criminal trial was aborted in late 2022 due to juror misconduct, with the charge of sexual intercourse without consent levelled at him later discontinued.

No findings have been made against him.

Evidence for the defamation proceedings opened with Mr Lehrmann taking the witness box, a place unfamiliar to him after he exercised his right to silence during an ACT criminal trial.

"I became severely isolated," he said, recalling being booted out of multiple friend group chats, widely blocked on social media, and "defriended" after Ms Higgins' interview aired.

But after telling the court about the "deep spiral" the allegation's airing sent him into, Mr Lehrmann was placed under the harsh spotlight of cross-examination.

In a tense and protracted back-and-forth with Matthew Collins KC, representing Ten, he was forced to explain why he had given three different reasons for drunkenly returning to Parliament House with Ms Higgins.

The barrister described the former Liberal staffer as a "fundamentally dishonest man who was prepared to say or do anything he perceived to advance his interest".

Mr Lehrmann accepted being mistaken in evidence to police, regarding alcohol in his office, and having lied to Network Seven's Spotlight program about the reasoning for lying to a political chief of staff.

Finally, the man at the centre of the proceedings repeatedly fended off a barrage of allegations.

He denied having any sexual intercourse, consensual or otherwise, with Ms Higgins, as well as trying to kiss her two weeks earlier, trying to get her drunk, or being "handsy" and "pashing" her at a nightclub hours before the alleged rape.

He would accuse the political staffer who told two courts she had seen the pair kissing on the night in question of colluding with Ms Higgins to give false evidence and "pervert the course of justice".

While Ms Higgins' assault allegation was at the core of the television broadcast and ensuing defamation trial, she was not obliged to give evidence. She opted to be Ten's principal witness.

"I was saying no and I was telling him stop and there was urgency to it but I couldn't scream like you see in the horror movies," she told the court.

Ms Higgins recalled feeling "avoided" by then-boss Senator Reynolds and "abandoned" by her political staffer colleagues after word of her allegation got out.

"[Senator Reynolds] actively avoided me and didn't even like being in a room with me," she said.

For the second time, Ms Higgins faced the unrelenting questioning of barrister Steven Whybrow SC in a witness box. But this time, while droves of people watched on via a livestream.

"Well, as I was being raped, it was not my primary concern where my dress was," she bluntly responded to repeated questioning about her failing memory of her dress.

"I was deeply more concerned about the penis in my vagina that I didn't want there."

Ms Higgins described the assertion she had fabricated her allegation as "insulting".

She was also forced to concede, "with hindsight", she had wrongly told The Project a leg bruise photographed in the days after the alleged incident was definitively caused by Mr Lehrmann.

The court heard Ms Higgins admit she had been wrong about some "significant matters" during the criminal trial but that she "did my best".

"Ms Higgins had a preparedness to tell lies, including elaborate lies, on the most solemn of occasions," Mr Lehrmann's lawyers later said in written submissions.

Ms Wilkinson and The Project producer Angus Llewellyn each took the witness box during the trial, vehemently defending their journalistic professionalism in putting together the television program.

Accused of being "thrilled by the riveting commercial appeal" of Ms Higgins' allegation, Ms Wilkinson responded: "Please don't make me sound like a cheap tabloid journalist."

The seasoned journalist denied supporting Ms Higgins without scrutiny. She told the court she believed there had been a "systemic cover-up" of the allegation orchestrated inside Parliament House.

Ms Wilkinson would also win her cross-claim battle against Ten, who was ordered to pay the millions of dollars in legal costs for her separately hired barrister.

That decision came after the court heard Ms Wilkinson was hung out to dry by Ten, which encouraged and legally approved a controversial Logies speech dedicated to Ms Higgins which delayed the criminal trial.

During his cross-examination, Mr Llewellyn was accused of trying to "do a number" on Mr Lehrmann by offering him a purposefully late right of reply ahead of the television program's airing.

The producer called this claim "ridiculous" after denying he buried "unanswerable questions" raised by Ms Higgins' evidence in pre-production meetings.

Mr Llewellyn was grilled especially hard for airing the photo of Ms Higgins' leg bruise, which Mr Richardson said was unverified.

The month-long defamation proceedings revealed a great deal of previously unknown details surrounding the case, including a number of secret settlement figures.

First off was Mr Lehrmann receiving $150,000 from the Australian Broadcasting Company and $295,000 from News Life Media Pty Ltd in out-of-court settlements.

He had separately sued the broadcasters for the ABC's airing of Ms Higgins addressing the National Press Club in 2022 and news.com.au's reporting of her allegation.

Documents published to the court website also revealed Network Seven paid for a year of Mr Lehrmann's accommodation as compensation for his multiple television interviews.

The country would also discover what the Commonwealth gave Ms Higgins as part of her previously confidential settlement deed.

The government admitted no liability in the payout, which netted Ms Higgins $2.445 million in lieu of her seeking legal action.

Just when the case appeared to be all but wrapped up, with Justice Lee slated to deliver his judgment: enter Taylor Auerbach.

The former Spotlight producer became the latest bizarre twist in the Lehrmann defamation saga when he alleged the former Liberal staffer had told more lies from the witness box.

The explosive claims would be enough for Ten to reopen its case, aiming to discredit Mr Lehrmann as a witness and delaying a decision.

Mr Auerbach was part of the Spotlight team tasked with courting Mr Lehrmann into a media exclusivity deal for two 2023 interviews. He described himself as a "babysitter, minder".

His allegations included Seven reimbursing thousands of dollars for massages, sex workers, drugs, dinners, accommodation and a golf game during discussions.

From the witness box, Mr Auerbach described Mr Lehrmann as being "on the warpath" one January 2023 night in Sydney, before going on a "bender".

He claimed Lehrmann agreed to do the Spotlight interviews while he plated up lines of cocaine and as he googled sex workers from a hotel room paid for by Seven. He was allegedly reimbursed in "per diems".

Mr Auerbach also alleged Mr Lehrmann leaked untendered evidence from his ACT criminal trial, including thousands of Ms Higgins' personal text messages and a pre-interview recording with Ms Wilkinson, to Seven.

If true, Mr Lehrmann would have breached an implied court undertaking not to use the evidence outside of legal proceedings.

Mr Lehrmann has denied all these allegations.

You can watch Justice Lee's decision on Monday from 10.15am on YouTube, after which it will be published on the Federal Court's website.