The media seems to have a double standard on this.
As I commented in this thread earlier today fines were also not levied on the Colac family, and all their party guests, for an illegal gathering which help to fuel the recent outbreak there, and the reason given was exactly the same as with the Casey Family Cluster:
Police are yet to issue fines due to concerns doing so might limit the amount of information partygoers are willing to give to contact tracers.
So interesting is it not that with the recent Colac Cases gained no significant negative reaction on this, but the same action with the Casey Family Cluster has created a large outcry from some in the media and is supposedly a major issue for some.
The right decision to not fine was made in both situations.