what's the usr.sbin in the path? why isn't that usr/sbin? this looks like some convention i've never met before (and i have no idea how to google for it...)
I guess it's there to flatten the source tree depth and probably had something to do with tiny disks of the time, shells without tab-complete or it was just a whim. In any case the convention stuck and it is now that way in all modern BSDs.