exterminate

Is there a way to complete exterminate missions where the only base they own is an abandoned settlement with zero members? I tried powerering up, pilfering, and then powering down the base. Soon after I was assaulted by a dropship party...of a completely different faction group! And sadly...

My first Odyssey combat mission, after somehow surviving the tutorial and doing a couple of "fetch" missions. Land at the base in question, get the total number of scavengers to kill, start shooting. Meanwhile at the same time, another CMDR is in the base doing a "restore power" mission, and...