Sorry to hear that ,about anyone no matter what they are shooting,it happens,don't like it when it does but it still happens. If it bleed for 50/60 yards,stopped and bleed a lot the went on with very little blood in my expedience it was probably some kind of flesh wound and more than likely will live,may stay hidden for the rest of the year but will live.
Flesh wounds start out bleeding good and then will usually tapper off,good hit will start out most times not so good and get better as a rule. Always bothers me when I start out right out the gate with a blood trail you can follow in a run and as you move along it seems to be slowing.
Not usually a good sign. I know what you mean about the big new style heads,a guy brought one down to the Deer Classic and it looked like it was shot with a broad ax,man what a hole.
Pappy