If you kill someone who's using a static weapon, like a machinegun, he will suddenly disappear from his position and appear lying down on the floor.
A little animation, or just a ragdoll falling down would be way better.
This situation is like this since Operation Flashpoint!
Related:
http://feedback.arma3.com/view.php?id=19946
Duplicate:
http://feedback.arma3.com/view.php?id=17013