Look at the result, the possible causes and the desired outcome. Two aircraft collide in possible IMC whilst conducting IFR training. Both aircraft are OCTA, class G in the vicinity of a CTAF. It would appear that both are on area frequency and communicating with ATC. One aircraft has maintained an altitude for the previous 30 seconds which indicates a separation standard was in progress. Without blame, what would have resulted in the best outcome of four good people still being with us today? Both pilots given and maintain an altitude till verified passage? Both pilots receiving positive vectoring? One or both pilots having , at least, an operational real time ADS-B Rx unit (certified or not)? Or, one pilot held on the ground till the incoming aircraft is visual? Class G obviously only works in VMC.
-Stop speculating on the cause of this accident.
-Wait for the ATSB to conduct the investigation.
-You don't know what you're talking about and have no right to speculate.
IFR pays for a service in Class E and above. Could this be amended to allow a service, even in Class G, if there is reliable spacial traffic information? THE desired outcome is a separation standard in IMC in ALL airspace within the ADS-B coverage map.
Stop right there Bucko
-It will cost too much.
-Nobody wants to pay for it.
-Who's going to pay for it all??
NOTE: Standard pprune response from the hidden residents.