Loot bug when someone hearths or leaves instance

What's the deal with loot on corpses bugging when in a raid and a member of the raid hearths, takes a portal, or leaves the raid before the loot is distributed. This is the second time I've witnessed the loot not being able to be looted and given to the raid members who won the loot due to one individual just leaving before it was handed out, and it bugs the corpse so the master looter cant give out the loot, effectively wasting everyone's time. I tried searching the forums to see if this is a known issue but I didn't find anything (I could of just failed at searching). Is this something GM's will assist with or are the winners of said loot just screwed and we get to just risk wasting hours killing crap just to see the loot rot because we cant loot the bugged corpse due to this?