Well, I'm not an aussie ATCO, however I can confirm that also in my part of the world there are pilots (the ones with the white gloves on), who apparently have the ultimate overview when they are flying.
Therefore they can assess if the holding they have to fly is un
nessecary and that the sep
aration was more than required (damn, we crossed them with 7 miles instead of 5!).
Educated (sic!) views from licensed pilots are demanded.
Put your (white) gloves on and give it to them!