Mr Pesutto faced questioning from Ms Deeming's barrister Sue Chrysanthou SC on Tuesday.
She focused a 15-page dossier prepared by Mr Pesutto and his leadership team, which was forwarded to party members as part of their move to expel Ms Deeming from the Liberal party.
During a heated debate, Ms Chrysanthou likened the dossier to a project by an eight-year-old who had copied and pasted things with little context - something Mr Pesutto strongly denied.
Sue Chrysanthou SC likened John Pesutto's dossier to an eight-year-old's project. (Con Chronis/AAP PHOTOS)
His barrister Matthew Collins KC spent much of Tuesday morning outlining the defence case.
He agreed that Ms Deeming's reputation was damaged, but said it was because of her association with an anti-trans rally and those who organised it.
Ms Deeming claims Mr Pesutto defamed her in media releases, a press conference and broadcast interviews following her attendance at the Let Women Speak rally in March 2023.
That rally was gatecrashed by neo-Nazis who performed the Nazi salute on the steps of the state parliament.
Mr Pesutto is expected to continue his evidence on Wednesday and Thursday.