They never seem to return for the item they gave you to hold. Are they bugged? Are they a clever way to be "gifted" items if your current items are too weak for your level? Are they not even that sophisticated, and just a random event that gives you a random magic item in a fun way?

I do think they should return for the item if the hunter dies or can't find them.

I have a sneaky suspicion that ratting out the fugitive to the hunter gets you a visit from a DB assassin later on. I have no proof of this, only that my first character (a goody two shoes) always gave the item back, and got attacked by DB assassins several times.

My current character has lied to the hunter and kept the item every time, and hasn't been attacked by an assassin even once.

While its a good theory, ive actually had the dark brotherhood come after me without doing any quests or even having a fugitive appear to give me a random item. on the funny side, ive had a bandit highwayman send hired thugs after me for stealing/pickpocketing him even though i killed him right after i pickpocketed him, that right he sent hired thugs after me FROM BEYOND THE GRAVE!!!!!