I have no doubt it was practiced during his tenure and laid the base for their normal processes:
"The latest serious allegations follow a 2018 investigation by 
The Age and
 The Sydney Morning Herald that revealed the systemic underpayment of wages at the restaurant group, which is part-owned by celebrated chef Neil Perry.
The investigation uncovered evidence that permanent chefs at Rockpool were required to do excessive unpaid overtime, a practice 
going back many years.
That practice pushed wages well below the minimum rates of the award, the wages safety net. Staff were being paid for 38 hours a week while regularly working 20 to 30 hours of unpaid overtime.
The Ombudsman has since launched an investigation into Rockpool Dining Group and the company has paid back $1.6 million for one year’s underpayment. 
Rockpool has since extended those repayments stretching back a further five years but has not detailed the total cost.
Rampant 'exploitation' at Rockpool restaurant empire