Mr Lehrmann took to the stand on Wednesday afternoon.
He told the court that former defence industry minister Linda Reynolds' team was relatively small in 2019 when she took over from Steven Ciobo and that there were no senior advisors at the time.
His barrister, Steven Whybrow, then took him through a number of tweets and articles that named him as Ms Higgins' alleged rapist.
Mr Lehrmann also spoke about a Facebook group he was 'booted' from within the week of February 15, 2021 - when The Project interview aired.'I recall logging into my social media accounts to shut them down because of the media furor,' he said.
Referring to Facebook, he told the court: 'I was removed from group chats and blocked in groups, my friend count had reduced which meant people had unfriended me.'
'When I was removed from these groups, [the administrators] would highlight in the messenger app that I had been removed.'
In another group chat with National Party supporters, Mr Lehrmann said one group member posted an 'eject' picture.
All members left the group chat and Mr Lehrmann was the only member left.
Mr Lehrmann said his life changed drastically after the The Project episode went to air.
He told the court people were 'defriending' him, 'cutting me off, removing me from group chats, blocking me, the list goes on'.
'I took an approach, when I was at Ramsay Northside, to shut down my social media because of the impact that was flowing from The Project.
'Then the media furor, after that and being named on social media and people were looking me up, posting things on Twitter, it was getting quite disgusting.'
Mr Lehrmann said he shut down all his social media accounts and has only recently reactivated Instagram and Facebook.
He also claims Ms Higgins invited him to drinks on the night he allegedly raped her.
Mr Lehrmann said his interactions with Ms Higgins that night were 'professional and cordial.'
Mr Lehrmann has continually rejected the rape allegations and strongly maintains he had no sexual interaction with her whatsoever.