When I saw what you'd done, Toast, I wondered if that would happen. Some years back I had a bear that came every year to eat the apples that fell off the tree. From the size of his crap piles I knew he was a monster. I installed a motion sensor to a loud alarm located by my sleeping head so when the bear came it would wake me up. Then my son, 11 yo at the time, could use a remote control shutter release from inside the house to fire off a tripod mounted camera and slave flash to get pictures of the beast.
Well, that motion detector went off like five times a night before I got it dialed in and got some amazing bear pictures. There was a coyote that followed him around and ate his poop.
See if you can get a friend to move around up on the hill with the system active. Use the data from that to set the sensitivity.