Right down the bottom of that link, it says "One finding raised was against Civil Aviation Safety Regulation (CASR) 172.115 in relation to supervisory personnel, which remains open."
CASR 172.115 says "An ATS provider must have, at all times, enough suitably qualified and trained personnel who are able to supervise the provision of any air traffic service that it provides"
I think it would be fair to confidently make the statement that Airservices do not have enough staff at Sydney TCU....and CASA knows it. Make of that what you will...
Alpha