Seems the F8 key, which increases bounty on the player closest to me on the list can raise bounty on dead players.

Situation occured when a bounty was raised on me, I quickly pressed F8, which then increased bounty on a dead player I had just finished off. Everyone had 0 bounty when it was raised against me. Although shortly after the AI started a bounty on another player which was higher than the dead one, which stopped me from raising it anymore. Would have been interesting to see what would happen if pirates sent an attack against a dead player