Broadcaster Alan Jones' claims of a cover-up over the deaths of 12 people in the 2011 Queensland floods have been described as "dramatic" and "sinister" in his defamation case.
Jones is being sued by the prominent Wagner family, who claim they were accused of the deaths in Grantham when one of the walls of the Lockyer Valley quarry they owned collapsed.
Brothers John, Denis, Neill and Joe Wagner are seeking $4.8 million in damages from the Sydney-based Jones, Harbour Radio, 4BC and journalist Nick Cater over 32 broadcasts in 2014 and 2015.
Closing submissions began in the Brisbane Supreme Court on Wednesday, dominated by debate over whether Jones had made a literal link between the Wagners and the collapse of the wall, and an alleged cover-up, or whether that was open to interpretation.
Jones' lawyer Robert Anderson QC argued the radio host's statements could only be seen as blaming the Wagners by an "unduly suspicious mind".
"The thrust of our submission is that the meanings by and large in this case just go that one step too far," Mr Anderson said.
The submission was labelled "fanciful" by the family's barrister, Tom Blackburn SC.
"Who is involved in the covering up? Apart from the government or the authorities, the only other people mentioned are the Wagners," Mr Blackburn said.
"The idea, Your Honour, that the ordinary, reasonable listeners would think the Wagners can't be involved in this cover-up is just fanciful."
Mr Blackburn also took aim at Jones' language during the broadcasts, particularly his description of the floods and the alleged cover-up.
"The day the wall of water surged through the town taking the lives of 12 people' - Your Honour, that's something like out of a movie," he said.
"It's dramatic stuff. It's sinister."
Mr Blackburn said Jones had acted as "judge, jury and executioner".
Justice Peter Flanagan warned Mr Anderson that Jones' honest opinion defence would fail if his allegedly defamatory statements were found to be substantially untrue.
Justice Flanagan also said he would have to consider the credibility of Jones.
Jones admitted during the trial his comments about the Wagner brothers were savage but said he and his team always took reasonable steps to be accurate.
A $2.5 million inquiry by then solicitor-general Walter Sofronoff in 2015 cleared the Wagners.
The Wagners have alleged they were also subjected to abuse, including accusations of a high-level cover-up, corruption and intimidation relating to their Wellcamp Airport.
The case continues on Thursday.