Moving forward, you will no longer be able to loot from npc corpses items that will later disappear from your inventory. Items obtained from an npc through other means might still disappear later.
What's going on is the items are not meant to be kept permanently, they're meant to go away when the temporary character retires. Previously, we would let you loot and use these items temporarily too, but they can cause too many issues when they do.
JUSTICE