One of the more cringeworthy moments of the robo-debt royal commission was when a Human Services official was asked about a focus group that had reviewed letters his agency was sending out, advising people they faced a welfare debt based on an average of their yearly income.

Only two out of a 15-person group could understand the concept of averaging. Asked if this meant there was a fundamental problem with the approach, the then head of Integrity Process Modernisation, Jason McNamara, gave a blunt response.