Got it twice in a row. Running void tier 1 capture. Got it about every tenth mission here (well, it FEELS like so, and we all know it's really hard to estimate probabilities w/o accurately writing down the exact results).
Well, IF there were more variants (not just silly extermination) - maybe then it will be a bit less of an annoyance... more like a little bit of unexpectedness added to the same level of annoyance, but still better... more like "less bad"... ;-)
And definitely not twice in a row! 0_o