The twinkling lights of Tokyo in the early evening were just coming into the view of Japan Airlines flight 052 when NSW Premier Chris Minns, sitting on board with his family of five, felt the phone vibrate in his pocket.

He was surprised. The phone was meant to be in flight mode. But more puzzling was the bluntness of the message that his chief of staff, James Cullen, had sent just hours into the premier’s first day of a 10-day family break.