Yeah, on its face I don't believe it either.
The number of hunters is down to begin with. And in that territory how hard is it to lose track of game that is shot?
I see this as an excuse for something the greenofascists have been after for a long time.
By and large, most of the Southern California mountains are arduous terrain, inhospitable to a hunter. It's steep, rocky, hot, dry, and covered with brush.