The executives of Ardent were unlikely to face prison over the deaths of four people at Dreamworld in 2016, according to law firm McCullough Robertson.

In a note released on Friday, McCullough Robertson said the timing of the deaths and the wording of the laws would make it difficult to prosecute despite scathing comments from the Coroner investigating the deaths who described a “culpable culture” of Ardent from the board down.

Even with comments such as this, it was not certain any prosecution could be brought against them because of a loophole in the laws.

McCullough Robertson partner Cameron Dean and senior associates Tom Reaburn and Liam Fraser said the industrial manslaughter provisions of the Work Health and Safety Act were brought in after the incident in 2016.

“In any case, even if the provisions applied, an industrial manslaughter offence would not be triggered as it only applies to the death of a worker, not other persons such as visitors to Dreamworld,” the lawyers’ note said.

They said an officer or worker could face five years’ imprisonment for breaching Workplace Health and Safety duty if found to be reckless, but this offence has rarely been used despite being available since 2012.

“The WHS laws, as currently drafted, make it more difficult for an officer of a large entity who is not involved directly in the day-to-day operations to be liable,” they said.

“The recklessness offence required the conduct of the officer to expose an individual to a risk of death or serious injury or illness.

“A prosecutor must prove this element beyond a reasonable doubt. From a legal perspective, this is a challenging task for officers who operate well above day-to-day decision-making.”