When the ground is noit even and I smacked down a zombie it slides, I can't use 'F' for inventory on it.
So I wait until the slide stops, then it also won't work.
Also the zombie glitches away when I look to it from several directions, mostly only one direction allows me to see it.
And it glitches away when I come too close.
As soon I go away a little bit or change the direction from where I look at it it appears again.
But still can't use 'F' to grab from inventory.