No, we killed the owlbear companion, the cub and the mother were alive at the end of the fight, when we left the dungeon. Ok, then probably the long rest triggered the death. I'm not sure now I saw the dead cub, maybe I just assumed it's death. Let's see wether the goblins have it. A pity I did not know this mechanic, we would have gone back without a long rest. Thanks for the hints.
