Same kind of thing happened to me on 3 separate occasions 1 after the recent update and 2 of them before. (date is 2/21/2015) Anyways when you kill someone you can look at their loot but can't take it into your inventory. However i have killed people and looted their bodies successfully. The only difference i can tell between bodies I can loot and ones I can't is that the ones I can't loot have fallen. One fell down a hill, another off a cliff. Both were dead before they fell. Also I could grab the attachments off of their guns. Ex. a long range scope, eject ammo, gillie wrap, and compensator. But I couldn't grab anything else. I tried to drag every item he had into my INV until he despawned. :(