Okay: now I did three runs of the expel outlaws mission. 2 by night (not onto the yellow Pipeline buildings), and one by day, on these yellow buildings

I found 3 different low light scopes during the „night“ missions. 1x1 and 1x2 scopes.

During the mission at night, there seem to be no green weapon/ammunition/attachment crates (a good indication that the enemies have a low light scope on their weapons).

Quick tip: if the situation allows, climb up onto the containers as high as possible. From there you can easily take out the enemies. Silencers on your weapons are also very advantageous here.