Dang!
Well ,once I skinned a deer that had a broken broad head lodged in the
rear hip,and when I got that one you would have never even thought anything was wrong with it bywatching the way it walked.[>:]

Maybe it rolled in some mud and packed the wound,my dad told me of one he
watched my cousin arrow,it pulled the arrow out with it's mouth and ran to a pond(40 yards or so)and rolled in the mud to pack the wound hole an ran off.
they never found that deer because they seen it a week later doing just fine!!

Get the kid out to get another one!!
This time tell the kid to take a deep breath and let it out before letting the arrow fly! Works for me!!