Alan Jones will continue to be cross-examined in the Brisbane Supreme Court on Friday as part of defamation proceedings against the talkback radio host.
The Toowoomba-based Wagner brothers are seeking $4.8 million in damages from Jones, Harbour Radio, 4BC and journalist Nick Cater over 32 broadcasts made between 2014 and 2015.
John, Denis, Neill and Joe Wagner allege they were blamed for the deaths of 12 people in the town of Grantham during the 2011 floods, when one of the walls of the Lockyer Valley quarry they owned collapsed.
They claim they were also subjected to accusations of a high-level cover-up with politicians, corruption and intimidation relating to their Wellcamp Airport.
Jones admitted to the court on Thursday his broadcasts had been savage, but he and his team always took "reasonable steps" to be accurate.
The broadcaster stood by his allegations the Wagners lied about the cause of the Grantham flood and the fact the quarry wall that collapsed was man-made.
Jones also maintained his claims the processes involved in the family receiving approval to build the airport at Toowoomba were corrupt.
Barrister Tom Blackburn SC repeatedly accused Jones of grossly irresponsible reporting because of his failure to tell the family about the "grave allegations of misconduct" he was going to make on air.
But Jones said his team had previously contacted them and the Wagners had made it clear they wouldn't speak to him.
"I'm not going to waste my time calling people up who won't speak to me," he said.