Really? How can an autopsy do this? (seriously, I'm curious)
defensive wounds maybe? blood splatter?
Raise your hands up and notice how your muscles and bones are moved. The bullets path will tell a lot about the position the body is in when struck.
Methinks muzzle-flash burn marks (it was close range) on the forearms if hands were up.
The examiner, in certain body areas, can match the entry wound with different body position. If hand are high in the air, the hole in the muscle will look different compared to lowered hands. If is a matter of moving body parts until the bullet fits thought the hole. I am sure FR doctors can better explain. Obviously this does not work with a head shot.