I’m struggling to answer the who and why of the cameras.. but I keep coming back to Cas and because of his notorious money issues. I don’t think he would do anything to hurt you intentionally but I think it’s possible he was financially motivated to set up the cameras to catch cryptid hunters becoming the hunted. Maybe he’s being blackmailed but it might serve to ask how his personal life was going before he returned (maybe he didn’t ask off work and was actually fired). He put on quite a show while interrogating your employees and then the note shows up basically immediately after (was it handwritten?). My other thought is that the cameras spotted the white rabbit. Maybe you could secretly watch the film to get an idea of its location - unless Cas kept the SD cards…. I hope I’m wrong OP,