Perhaps it is just really bad luck but in "The Creator" mission I have had huge amounts of trouble with feign death with these mobs (and only these mobs); started happening after the last patch.
34/34 times a combination of both regular feign death and last breath rkK II have failed on a lvl 76 SK. IF (and I stress IF) true it is likely to keep peeps (like me) from running the mission solo (with a box group member with merc standing outside of the instance) utilizing feign to get to the mobs, and harm touch/leech touch to knock the entire creator mission out in <14 minutes solo.
Too bad, was a nice source of faction while it lasted.