I completed it as of a week of so ago. Ran his arc with a team of 3.
i complete it everytime. it just happens that sometimes an npc from a patrol will fall through a hole in the map or just spawn outside the map.
Good to know. Next time I'll complete it w/o paging a GM, I swear.
you won't be able to finish if they fall off the map or spawn outside it. well, unless you restart the mish. but keep your fingers crossed next time. 
I did this mission last night (Defeat the Malta Group Invasion from Daedalus) via flashback. I did this b4 while I was levelling and had to page a GM to complete. This time I swore I would find all the Malta. Of course, I did not and had to page a GM. This time however, rather than "teleport" the last dude to me, the GM auto completed the mission saying there was a bug. So I'm now wondering if this mission is actually a "bugged" mission or was I just "unlucky" twice? Anyone completed this mission on their own?