How hairy were the stems and leaves? How many bracts were there behind each flower head? Were the bracts broad or narrow? Were the bracts longer or shorter than the leaves? What colour were the leaves?
While this plant is clearly in cultivation at STEP, its compact habit suggests Pimelea glauca. The only other common white-flowered lowland pimelea that it resembles is P. linifolia, which normally has a rangier, more open habit, growing up to 1 m or more in height. See: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Pimelea~glauca. Habit shots and close-ups of leaves would be useful.