Human error, not an attempt to escape further scrutiny, was behind incorrect advice the Queensland government relied on to fix issues within its DNA lab, an inquiry has been told.
Managing scientist Cathie Allen on Thursday began giving evidence before a commission of inquiry investigating a 2018 decision not to test crime scene samples with low amounts of DNA that fell under a certain threshold.
Questions centred on Ms Allen's actions prior to a decision by the Queensland government in June this year designed to revert to pre-2018 processes where the low DNA samples were tested.
She agreed that standard procedure at the lab before 2018 was for samples with low quantities of DNA to go through a process described as micro concentration before amplification.
It was regarded as the best way of achieving the highest proportion of successful DNA profiles, the inquiry was told.
When asked for options to change the lab's processes, Ms Allen said human error was behind her advice that stated amplification without micro concentrating was the preferred option.
"I didn't describe it right, and I also then didn't put forward the preferred option," she told the hearing via video link.
The process of going straight to amplification was cheaper and resulted in less of a testing backlog, the inquiry was told.
Commissioner Walter Sofronoff asked Ms Allen if she thought the Queensland government cared about spending $20,000 every six months if it knew it would result in "the greater likelihood of serious, violent crimes being solved".
"That's what I was asked to do, to put forward costings within (the options)," she said.
Ms Allen rejected a proposal by counsel assisting Michael Hodge, KC, that she deliberately provided false information so the change in workflow was less likely to be successful in producing DNA profiles.
The reason she would do that is so the 2018 decision did not look as significant as it was, Mr Hodge suggested.
"That's not true," Ms Allen said.
She also rejected the idea that she framed her advice as the "pre-2018 workflow" so it would be assumed what was being switched back to was the process in place immediately before the 2018 decision.
Ms Allen said she told Queensland Health staff about the error in August.
Her evidence continues on Friday.
