So that's a different scenario: in dungeon zones you can claim multiple mobs in very close proximity as a camp. In this case, it sounds like the group did have the claim to the camp, because they had killed a (different) mob previously.
However, I (greatly) sympathize with your point that it's impossible to know what counts as a camp sometime, and the staff does change their opinions from case to case. I also sympathize with the staff: having to consult a rules bible every time they interact with players would make their (volunteer) lives much harder.
My "solution" has been to put a lot of time and effort into
https://wiki.project1999.com/Camp_Rulings. It doesn't yet have a ruling for Vilefang, but if you can post whatever the GM told you (and when) I can add it, and it will at least help educate future players.