Game Camera "problems"

We keep getting an animal that tests the range of the PIR and trips the cameras off..the other Day, Craig set up a road kill wallaby in the fork of the tree and then set up a game camera facing it..the camera works fine..something came in at night and ripped the cable ties off the tree that were holding the wallaby body and took the carcass.
It did this from the rear of the tree and didnt get even moved to the front of the tree at one stage and still the camera didnt record it..very odd stuff indeed..