Hi,
I used weakness (dark way spell) many times so it killed the rat but when I tried to loot the rat I couln\'t saying that I\'m not allowed and yes it\'s me who killed it coz there was no one around.
EDIT:
After some test I found out that this happen with freeze too..
It killed the rat (0,0% of life) but the rat was still moving and I had to kill it with sword.