I worked in facilities for a number of years (in the US). Exterior lights are normally on a timer or otherwise synced to dawn and dusk, so it is normal for them to all be on the same system. I find it unusual this issue would not have already been resolved at a large, prestigious place like the Vatican. You want the walking areas lit at night for safety.

Edit: Oh, nevermind on this whole thing. They literally dimmed out the live feed itself to make it look darker.