Spectators will still appear even on a later conquest on the same planet, and killing their stuck cloned ship will also kill them, wherever they are. Happened to one of my clanmates, he got podded in orbit because its clone on cosmo got killed. Happened to me while i was in Venar LZ, i was podded in middle of the map and my ship appeared right on my pod, i couldn't do anything until units killed my "real ship" as well.