IF an incident like this were to be properly investigated, a number of systemic faults would be revealed.
The whole reason for using radar is that you can "move" more aircraft in a given airspace with radar than you can do without it; you can reduce the separation standards to 3 miles because you can "see" the aircraft on the screen.
BUT precisely because you are reducing the separation standards, the safety case of the use of radar must have a whole raft of safety mitigations built in so that no single failure can make aircraft less safe.
Hence SYD is served by at least two different radar sensors which normally feed a common radar display processor but can also feed directly to each separate ATC console.
Duplicated power supplies, duplicated communications paths etc etc exist to protect against failure.
Airservices is supposed to maintain a safety case that demonstrates how safety is maintained in the event of the inevitable failures of component parts of the system. CASA are supposed to audit Airservices to ensure compliance.
It follows that this "incident" demonstrates a failure of the safety system and of its oversight.
But will ATSB, under the leadership of an Ex-ATC safety manager, truly get to the bottom of this foul up?