Okay, did I miss something with this quest? I rescued IJ and released him after exiting. He went "poof" and the quest is still in my log. What am I missing here?
Nope. After letting him go the first time with no quest completion, IJ mysteriously re-appeared in my inventory after switching streets (and after posting about the bug). Not sure what happened there, but I released the second mystery IJ and subsequently now have the quest complete. Strange, but must have just been an actual glitch.