Based on location my guess would be Daviesia genistifolia. There is a population of this locally rare plant in this reserve. Daviesia genistifolia (Broom Bitter Pea) Also looks a bit like Acacia genistifolia, but I'm not aware of that in this location. Genistifolia refers to a likeness to the genius Genista, broom. Neither look much like broom to me...
it must have put on a lot of new growth since spring, and lost all its seeds, but I suspect you are right Claire. The locations I found them would be about right! Just looked less stiff - but we've had a great deal of rain!