Yep, that is a bug. Their escape pod should be removed when they self destruct.
It's not a big bug as they have lost all of their planets even though they can log back in they are starting only with the money they have on their ship and bank. And their ship is a pioneer. So they really hurt themselves. No way to exploit it.
But I have fixed it in our games and it will be patched in the next release.
Thanks