During a dramatic day in court described by one observer as "better than an episode of The Days of Our Lives", writer Ronald Suresh Roberts vigorously defended dubbing DA leader Tony Leon's father "a hanging judge".
And he denied suggestions that he was a name-dropper who ingratiated himself with people of power.
Roberts notoriously fell out with Nobel laureate Nadine Gordimer while writing her biography and is currently writing a book on President Thabo Mbeki.
He was in combative form on Tuesday in the witness box at the Cape High Court.
Roberts is suing Johncom Media Investments for R300 000 for an allegedly defamatory article that appeared in the Sunday Times in 2004.
The article, by journalist Chris Barron and headed "The Unlikeable Mr Roberts", includes allegations that:
Roberts - born in London, raised in Trinidad and educated at Oxford University and Harvard Law School - alleges he was not given the right of reply on two issues in the article.
He spent most of Tuesday clashing with top lawyer Wim Trengove SC, for Johncom.
Trengove repeatedly told Roberts to answer his question; Roberts repeatedly demanded of Trengove that he be allowed to answer the question as he wished.
At one point he told the advocate: "You really need to keep this straight - Mr Trengove, I'm having to spend a lot of energy correcting you on my evidence."
Trengove drew occasional laughter from the gallery as he expressed incredulity at some of Roberts's responses.
"Oh Mr Roberts, Mr Roberts - that's an absurdity, isn't it?" he said at one point, to which Roberts replied forcefully: "I disagree."
Roberts, who "outed" Tony Leon's role as a reporter for Paratus, the then SA Defence Force magazine, during his apartheid-era national service, was questioned closely by Trengove about an article in which he described Leon's father, Mr Justice Ramon Leon, as "a hanging judge".
Judge Leon, who served on the Natal Bench, sentenced 19-year-old Andrew Zondo to death for his role in a 1985 Amanzimtoti shopping centre blast that killed five people.
"A 'hanging judge' can never mean a judge who once imposed a death sentence?" Trengove suggested.
Roberts: "I disagree."
Noting that Roberts had referred to Zondo as "Mathew Zondo" on two occasions in print, Trengove said this indicated he had done "no research whatsoever" on the subject.
Roberts said he had re-searched the subject several years earlier while writing a book about the TRC with Kader Asmal.
"Andrew Zondo is dead - that's a fact. It's a famous (death). It (the use of the wrong name) was a semantic slip in a long series of debates," he said.
Trengove questioned Roberts about his use of names of prominent people in various items of correspondence and in some of his verbal replies in court, suggesting he indulged in "sheer name-dropping".
Those mentioned included: Nelson Mandela; Kader Asmal and his wife Louise; the only African-American in the US Senate, Illinois senator Barack Obama; current Chief Justice Pius Langa; Deputy Chief Justice Dikgang Moseneke; former SABC board chairman Vincent Maphai; Ambassador to the US Barbara Masekela; political heavyweights Trevor Manuel, Cyril Ramaphosa and Jay Naidoo; Winnie and Zinzi Mandela; and the presidency of Mbeki.
Roberts repeatedly denied the name-dropping charge, saying on one occasion that he had done so to make an ironic point and elsewhere describing it as "standard practice in the corporate environment called 'networking' every day of the week in Johannesburg".
Roberts denied the Minister in the Presidency, Essop Pahad, had exercised any editorial control over the manuscript for his book on Mbeki, which was sponsored by Absa Bank for R1,2-million and other amounts by other undisclosed sponsors.
He also denied a suggestion by Trengove that he had "viciously" criticised the book on Thabo Mbeki by journalist William Gumede.
The case continues on Wednesday.