Some people on here have said they don't expect the ATO to target pensioners, not Centrelink.
Not going there again.
You seem to be confusing Centrelink and the ATO's duties.
It's not up to Centrelink to chase residents or non-residents.
They will chase people owing debts to them.
Residency and non-residency status will be determined by the ATO, but It's no use going down that rabbit hole again.