I accomplished the bandits quest in normal difficulty, and for some character build reasons, I need to recall which option I chose (save one of them or kill them all). Does it appear somewhere ? I couldn't find the information in the "journal" (let's call it that way), under the world map.
There are four ways to find this out. You can remove all equipment and count your stats.
The second way is by visiting the bandits, starting with the one you most likely helped.
If they have an exclamation mark above their head it means you killed them, if not then they are the bandit you helped. In my case I helped Oak, as the pictures show. You can also re-kill the ones you previously killed for drops if you want.
Another more direct way is to talk with Eramir. One of the conversation options will be about the person you helped.
The fourth and easiest way is to look at your quest log.