Bindook, thanks for the analysis on what Aminta said, but sometimes the controllers do take an active interest in VFR aircraft separation. As she said, "...and they haven't been separated by air traffic controllers." That means that the ATC haven't seperated them. She never said that they shouldn't be separated by ATC. Maybe she is trying to highlight a point- The infrastructure at bankstown didn't alert them to alert the pilot.
A simple latent failure- or the neglect of a running down airport?
Shouldn't Bankstown have a radar (it does

; a radar screen is in the tower if you go up and have a look. It piggy-backs sydney's)? Shouldn't bankstown's controllers have an aircraft proximity warning alarm? There is one at Sydney- I think!
Just for thought.
May God bless them.