Great questions, IMHO and again, IMHO, needed to be addressed at the scene/time of the incident!:banghead:
BBM............Just addressing the question of blood flow....the amount of blood would be significant as the upper torso/chest area (where the shot is suppose to have hit) is very vascular. Adding to the primary vascularity of the body is the the perfusion of blood in the internal organs (the lungs & pericardial sac with the heart itself) that if punctured would result in massive blood loss. With a "hole" in the skin and agonal blood pressure, the "rolling around and scuffling" would permit the exiting blood to flow onto/into any available surfaces.
Example: think of a fluid filled toy within a balloon....break the surface of the balloon, air leaks out but if one punctures the balloon & the toy, both air & fluid pour out.