I'm having a stab in the dark here. Looks like two robberflies mating, but either before or during one of them has picked up a snack. Maybe a native bee. ? which is making the whole shape look very weird. Though never seen robberflies with yellow on the legs before.
I agree there is a robber fly in there, and it's caught something else, maybe a flower wasp. The Robber fly Daptolestes limbipennis has splashes of yellow on the legs which match this one.