Australia Post chairman Lucio Di Bartolomeo has conceded Christine Holgate was treated “abysmally” in a firestorm sparked by executive bonuses, but won’t quit or apologise to the former chief executive.

Describing her as an “otherwise highly effective” boss, Mr Di Bartolomeo said Ms Holgate had made a good faith error of judgment by spending nearly $20,000 on watches for executives – moves that sparked controversy for the Morrison government and led to her departure from the taxpayer-owned corporation.