Well im bumping this thread. Just tried the mission and all devidians and feds are dead but none of the klingons. Last time I did this mission on holodeck it was bugged, but there was only 2 npc's left and I could still take out the rest of the devidians and finish the mission>
Not now, all klingons are alive and there is no other devidians anywhere!!!
Another solution we found to be working is to attack the devidians only. Don't even shoot the klingons or the feds. Your BOs doesn't seem to matter, but if you start blasting everyone, it bugs. We did it quite a few times, only trashing the devidians in the bar resolved it automatically without a hitch.
Edit: Klingongs.. geez my morning trekish sucks xD corrected.