Logging out in the middle of combat.

My brother and I cornered a 4 man galley and started unleashing hell. As their ship was about to sink, they logged off and the boat disappeared. It didn't sink as if scuttled, it just entirely disappeared instantly. I'm not sure how that affects any treasure that may have been on board, as I'm fairly certain that they offloaded any booty they had first. I just think that you shouldn't be able to log out like that if you've taken damage in the last 3 minutes or something, or if you did, you lose your treasure as if you were sunk.