I don't know anything about map editing, but I think this may be related to a prefab. On the way out of Linz, things get a little dark as soon as you move into the area covered by the right wall you see in the video. It's not a big deal, but there is something going on there.
Looks like it's the HDR/Bloom effect which disappears in the "shadow" of the wall
This signature virus has been spliced with the Fundementalism-B virus to create a new more contagious strain. Please look for it infecting a signature near you.