Not enough info to make an educated guess. But if you had white hairs, they are found on the "edges" of the deer (brisket, belly, tail end). Because you were 30 yards away, it is unlikely that the angle of your arrow could take out the vitals and still get this white hair (if the deer was completely broadside and didn't spin or turn as you shot) Give it 3-4 hours and start searching. Good luck, let us know what you turn up.