Hey MD: very good column.
One additional factor I've read about (but don't remember the reference) but which sounded credible, came from a study conducted during Cape Buffalo culls in S. Africa some years ago. A veterinary pathologist tried to differentiate what happened between chest-shot animals that dropped-right-there, versus same shot that ran-then-died.
During necropsy he reportedly detected evidence of cerebral stroke in animals that dropped/died quickly, and credited that phenomenon to bullet strikes as the moment of peak systolic pressure (heart contraction) rather than at the lower diastolic pressure (heart relaxation). His theory went that when a Cape Buffalo died instantly (or at least was incapacitated instantly) the cause was a pressure spike causing internal brain bleed or profound neurological stunning. And given the impossibility of timing such a shot to cause cerebral stroke, the outcome of each shot was random, and couldn't be perfected (at least not with a chest shot).
What do you think of this theory to explain any of your observations?
