When my alt, Bagheera, killed 2 scorpions on her own, for the scorpion mission on Exodus 2 days ago, she was not credited with contributing to the mission in any way.
I also killed scorpions for this mission, was credited with the kills, but did not get 30 minutes of SB once the mission was completed today, even tho' I had less than 2 hours SB left.
Thus, it would seem that this mission was somewhat bugged.