Years ago I remember my brother left a baseball scorebook at the Four Seasons Houston. He called and they agreed to mail it back, They also mailed back a ton of stuff he'd also left behind with it (including I believe a pair of boxer shorts) so it's certainly possible.

I worked for three years in car rental and I can say that very few items of any value were turned in by any of our employees. I know someone came back to me five minutes after they returned their car stating they'd left something in it. We got to the car shortly after it and whatever item it was had already disappeared. Of course no one knew anything