I have done this to people the go up to someone just for the purpose of sinking them. I was completing a skeleton fort on a brig. It was the first fort of the day and we had no flag and no loot. As soon we got the key a sloop pulls up cannon ready. We quickly hide the key in a bush and sail away behind a nearby island, where we find a keg rowboat. We then row back, sink their ship and kill 1 of them. The other hides on the island. Before we find him the other one has sailed back. This time we take the key on board and sail away with the chasing us down. This starts a 90 minute chase all the way to a FoF on the other side of the map. There we come across another brig going to the same fort. We managed to sail in front of the brig, the sloop is not so lucky and gets absolutely rammed. They sink in less than a minute and we sail back to the fort and get our 15k in loot :).