Sucks for your buddy. I personally would never leave anything on public property over night. That just screams "steal me."
On a side note, I ran into a trail camera for the first time ever a couple years ago on a piece of public land I've hunted since 2002. Decided to sit across from it for the noon opener, since it was a good spot that I'd hunted a half dozen times. The camera was swinging open, so whoever owned it had pulled the card and batteries but left the actual camera (God knows why). Got there about 10:30. At 11:45 a kid comes down and asks what I'm doing there. I thought the blaze orange jacket and rifle in my hand was a clue, but I spelled it out for him. He got pissed.
"Well that's my trail camera, I'm sitting there."
I kind of looked at him funny and asked him how long he'd owned the public property we were hunting.
God I hate rifle season.