I will try to do this without real spoilers, but if you play 22 characters, you know most things after the first one or two so...

Practically the earliest available quest involves a town having gang problems; you have a reason to visit the town and then need to help them to continue the quest. You find the gang and have many options (kill them all, talk, negotiate a settlement...the usual type of spread). If you take the paths that my first character did and successfully ended the problem with friendly mutual relations, the gang will send a member to the town as liaison and future help. I watched him go, left the level myself, and continued on. A few (in-game) weeks later I came back and the gang was hostile to me; I went to the town and the town was also hostile; I went to the quest source and she said she knew what I did and I could just be off with myself. But not that polite.

The member who was sent had gotten killed. Other threads list him killed at the town by beasts or something, resulting in both groups becoming hostile to your character. This is in spite of the fact that I had highest Karma and did nothing to him or them. It's a glitch that should be patched.

But here's the kicker: when he died for me, he died on his home level; I was just ahead of him and saw it. You see, the gangs hideout is booby-trapped. Mines; trip-wired, you name it. Now my own mines don't trigger for me. And this gang comes and goes all the time so theirs shouldn't trigger for them. However this guy took a trip-wire and then a bit further on set off a mine (one of theirs: I couldn't touch it except by stealing). I thought they were hostile because my being in the level triggered the ai to my being the only cause; but now I see that even if I disarmed everything on the way in, or left fast and he (practically) teleported to the town, any later death of this guy tags me as a bad guy. The npc self-inflicted trap thing is a design flaw. They should be immune from their own (at least the mines, since pc's are).

Next character I'll sprint out of there to the originator to see if I can get the quest closed as a success before the guy gets wasted and I get blamed after the fact. Does anyone who successfully got this quest done know if the hostility mistake arises if this guy dies AFTER the quest is tagged as "completed" ? Is that where the bug lies or does it just happen anyway?