Around legal circles, Mark O’Brien is known as much for combative letter writing as his clients’ notoriety. Recently, those clients have received an unpleasant lesson: defamation lawsuits can destroy tarnished reputations rather than restore them.

Last week, Nine Entertainment Co’s legal department received a $1.2 million cheque from performer Craig McLachlan, who unsuccessfully sued the newspaper publisher, and the ABC, for accusing him of sexual impropriety.