Ok, I am going to chime in here.
First, a high shoulder shot IS a CNS shot.
Second, if you don't hit CNS with something, then you will never get a reliable DRT animal. PERIOD. Even the "I shot it behind the shoulder and I got a DRT" shots, if you do a good necropsy, you will find that a piece of bullet or bone hit the CNS. All mammals are built such that they can take a good amount of abuse to their internal organs and still function for a while. You have to sever the connection between the brain and those organs in order to get a "lights out, right now" effect..
This is not true.
I have killed several deer that were DRT with a bow. Those deer had untouched CNS. They did not die instantly either..
Two hit the ground and died within seconds, one took a minute or two. 
