Personally, I'd be excited for this to be true for a number of reasons:
* I'm Australian. Any advance in the understanding of how fires spread is of material benefit to me and people I care about.
* I love animals. It'd be amazing if another species used fire, and may open up whole areas of research.
* I'm Australian, which means I take a bizarre pride in our image of having the most dangerous wildlife in the world. The existence of fire-wielding raptors would turn this knob to 11 :)
But I'm afraid I'm still betting "bush legend inspired by old Aboriginal myths" on this one.
It's true that most people flee fires, but a lot of people observe them closely, these days with some very shiny equipment (including IR cameras on helis, to see thermal sources clearly through smoke).
I'm fairly (but not entirely) sure that this behaviour would have been observed already if it were true.