Without being able to envisage who should have been where and when, I can't comment on who was at fault for the accident. All I can say is that it should be illegal for three people too be riding the same motorbike. However, in this country who knows. All I do know is that the Aussie will be found to be responsible. Legally, here a car never comes of best in this sort of situation.
RIP to the poor young'ns killed, having three daughters of my own, I can't imagine what their poor parents are going through.