Game Mechanics: Skill-up oddity

[BarackObooma]

I thought I had put in a ticket for this a long time ago but can't find it. It's fairly easily to replicate. I had made a level 1 halfling mule to corpse no rent items from the shadow men. I'd bag drop them and have the mule attack a npc. Many times it'd skill up something, 1hs, defense, offense, etc. but once you respawned, the skill up wasn't there.