Some people are phobic about blood producing injuries. Dentists see this quite alot. Thus, if their finger or toe was shot off, they would pass out.
So it is possible.
Anyway, shoot what you see first. At the NTI, we had a tricky situation where a torso and head would pop out. However, there was a leg that was constantly out there. If you waited for the head, you were chastized. The leg was a freebie - take it.
Same thing in another FOF, there comes a big leg - bang. So the rest of the interaction is me being whole and the opponent with a big hole dead center of inner thigh.