Ms Higgins is fighting her former boss, senator Linda Reynolds, over a series of social media posts the ex-defence minister believes damaged her reputation.
Defence lawyer Rachael Young told a Perth court Ms Higgins' rape in 2019 caused her much suffering and gave rise to a "profound and lasting impact" on the way gendered violence and safety issues are addressed in Australian workplaces.
"Ms Higgins spoke out about her ordeal," Ms Young told the Western Australian Supreme Court on Monday during closing submissions.
"This was for an altruistic purpose to ensure that there would be a focus on systemic failings at Parliament House."
Brittany Higgins' lawyer says she was altruistic in speaking out against her treatment as a staffer. (Bianca De Marchi/AAP PHOTOS)
Ms Young said Senator Reynolds had launched the case against Ms Higgins in a bid to restore her reputation by laying the blame for the loss at the feet of one of her most junior staffers, who had been raped, for three social media posts in 2023.
"The dogged focus of the senator exemplified by both her evidence and the 25 witnesses that she called demonstrated ... how the senator felt after The Project interview ... and what she saw as a politicisation of Ms Higgins' rape allegation," she said.
"We say that that focus demonstrates the meritless nature of her claim ... against Ms Higgins for publications in 2023.
"The senator's focus has been on the wrong target."
Ms Young said Senator Reynolds' own evidence revealed that her hurt, distress and health issues in 2021 had no relationship with Ms Higgins, 2023 social media posts.
"...the senator seeks to attribute a sinister and gratuitous improper motive to Ms Higgins and boldly says that the 2023 publications were actuated by malice in pursuit of an alleged conspiracy plan formulated in 2021 ... (to) destroy the senator and bring down the Morrison government by weaponising Ms Higgins' rape allegation."
Ms Young said the senator had failed to prove the allegation and the attention in parliament and the media to Ms Higgins' accusations over a cover up and mishandling of her alleged rape was to be expected "by way of political accountability (and) it's not improper".
Closing submissions are underway in the court case between Linda Reynolds and Brittany Higgins. (Mick Tsikas/AAP PHOTOS)
Ms Young said the scrutiny on Senator Reynolds in 2021 had been intense and unwelcome and it was brought on by questions in parliament, the senator's conduct when she called Ms Higgins a lying cow and the fallout that followed.
"It is also a significant factor that the senator had pre-existing mental and physical issues, and ... that she was unable to retain the defence portfolio due to her ill health," she said.
Ms Young said 2021 was a tough year for the senator but the evidence also showed she had gradually improved over the following three years.
She said there was little evidence to show the senator was harmed by the social media posts and Ms Higgins' justification defences are made out.
"The evidence identifies (the senator) harassed Ms Higgins, including by leaking confidential and privileged documents to the media," she said.
Ms Young also said Senator Reynolds' conduct during Bruce Lehrmann's aborted rape trial gave the "impression that she was partisan in favor of the accused".
She said Ms Higgins' social media posts were also protected by statutory and common law qualified privilege and by the defences of fair comment and honest opinion.
The trial continues.
