Perhaps it was the long hours in court on Thursday, the head-spinning technicality of the legal argument, or her trademark irreverence.

Whatever the impetus, Sue Chrysanthou, SC, the whip-smart legal counsel for Lisa Wilkinson, threw the switch to vaudeville late in the afternoon as she conjured up ever more improbable reasons why – if there’d been no sexual act – Brittany Higgins had been found naked and passed out on a ministerial couch in the early hours of March 23, 2019.

Lisa Wilkinson and her barrister Sue Chrysanthou, SC, outside the Federal Court in Sydney on Friday.Credit: Flavio Brancaleone

Had the young staffer, returning to Parliament House with colleague Bruce Lehrmann after a night out drinking, taken off her lightweight dress because she felt hot? How did that make sense? It was Canberra, after all, the barrister remarked unkindly. Had there been “some kind of freak heat wave” in the national capital that day and the airconditioning had broken down?” No, she argued. There could be no other explanation for Higgins’ state of undress, she told Justice Michael Lee, other than “that sex occurred”. (The temperature in Canberra that night was 16.7 degrees at the airport, according to Bureau of Meteorology records.)

Chrysanthou’s brief foray into absurdity had deadly serious intent.

For 4½ weeks, Network Ten’s legal team and Bruce Lehrmann’s lawyers have been sparring over whether or not he raped her in then defence industry minister Linda Reynolds’ inner ministerial sanctum.

On the cusp of Christmas, the defamation hearings have drawn to a close in Sydney’s Federal Court, and Justice Lee has retired to consider his ruling.

If he finds, despite Lehrmann’s denials, that a rape occurred, then the network’s truth defence triumphs and it will win.

Bruce Lehrmann outside the Federal Court in Sydney on Friday.Credit: Flavio Brancaleone

If not, Ten’s lawyers will need to fall back on their secondary (and more perilous) defence of qualified privilege, which requires them to show reasonableness and care in handling the story. The network’s assertion that it did show such care has been under repeated challenge during the course of the hearings.