Yes, it's annoying, but for some reason it's a feature in potco and tlopo where if you end up at these island unintentionally, you automatically magically turn into french/spanish pvp. This may have been a convenient programming device and proper for pvp continuity. But as you found out, it's a bane for the non pvp pirate getting dumped to that island.
There's only three solutions to that dilemma. Easyest is to log out, not always desired. Second, to TP to main other islands. Don't have TP? Then third is to keep trying to move away from the island as fast as possible. But after numerous sinkings, we mostly end up logging out anyways.
There may be a forth way as well. Join a public ship that shows no pvp colors. That has worked too.
GL