Why is everyone so hung up on flying from Alice Springs. The plane departed Halls Creek that morning.
Probably because all the reports so far have stated Alice as being the point of departure? That said, it seems a pity that he didn't have enough fuel to divert elsewhere or at least find somewhere a bit more promising to park it, when it became evident Broome was socked in.
Of course this is the usual thinking aloud and extrapolating from news reports; there may be a perfectly rational explanation, but it's amazing how often the obvious answer proves correct on these pages.