Has something been changed here? With my first two characters I could fight and defeat the mimic or the wolves wiithout anyone else getting involved. Today with my 3rd character I fought the mimic and suddenly the Red Sash Bandits including Blackpond charged me to fight me. And when I made a tactical retreat towards the exit even Kelly Hayward followed me and punched me with empty hands...
You're talking about the Owl's Nest Mine, right? All the humanoids use a neutral faction variant we call the "Red Sash" faction, including Blackpond and Kelly Hayward. This means that each one will avoid fighting you unless you fight first. It also means that if one of their allies detects you started a fight with their friend, then they'll join the fight against you. However, if you start a fight but avoid fighting them in a way that allows them to stop being aggressive, they'll go back to a neutral, noncombative state. The wolves are normal wolf faction, which means they're aggressive and will attack-on-sight any humanoid in the area. The mimics have their own faction, which also gives them an aggressive "attack-on-sight" behavior. My assumption is that you may have accidentally attacked a humanoid, perhaps as part of an area attack, which triggered the Red Sash aggression behavior.