The $1.8 billion robo-debt scheme relied on a hit-and-miss approach backed by a single piece of internal legal advice based on a “vibe”, Royal Commissioner Catherine Holmes says.

Her observations came as the operator of the robo-debt scheme, then known as the Department of Human Services (DHS), relied on assurances from its mother organisation, the Department of Social Services (DSS), that a welfare debt could be raised using a recipient’s yearly income averaged over the year.