Well...it could be interpreted as using that as your "aiming" point so to speak. For instance, when I throw a hook or uppercut, I basically control the contact point through the outside knuckles, otherwise if I "lead" with the first two, I bend my wrist to try to land it (which in essence, would mean suffering a hand injury)... Doing it the other way keeps it sharper...at least in my explanation (which makes sense in my head. <_<) . So yeah...I guess you could say that *I* throw with the outside part of my hand, but land with the middle/inner by keeping my wrist straight after the final "snap". Feels weird trying to explain it in words.
Good example is actually the Winky Wright fight last night (if I recall the punch correctly). The knockdown punch. Look at the way the punch started, but the way the hand ended.