Black Plague unusually dark

[Human]

After finishing Black Plague, i went back to the area near the end with all the corridors leading to the kennels, etc, but my game was a lot darker than usual. I hadn't downloaded any pitch black cheats, but the game was almost pitch black without flashlights. It's as if the ambient lighting was turned off and only the direct light from fixtures left. This isn't really too much of a problem as it is now 3x harder and scarier as well, but is this unusual? And if not, isn't this what a lot of people want? I think a lot of players would like this.