From the look of the Flightradar24 tracks, offset tracking would not apply because the most efficient route meant that they crossed tracks, in this case just west of Adelaide. So in reality the situation wasn't really any different from any other where aircraft cross tracks at different altitudes. These two just happened to be less of angle than other crossing points.
In addition, the aircraft would not have hit even if the altitudes had matched. Sure, they came inside the mandatory separation distances and IF they were actually on a collision course they were less than 20 seconds apart, but it's very clear from the radar tracks that were never going to collide.
Sure, it's an incident and whatever tightening of procedures is required will be undertaken and we will all be safer as a result, but to suggest it was a near miss or that without evasive action the aircraft would have collided is baloney. Without evasive action the result would have been less separation, that's all.