If someone drops a $50 bill on the street and I come along after they are gone and pick it up, it is mine. It is not stolen. It is lost. I am not liable for the other person losing their $50.
What? Really? You'd do that? You'd not be like: "hey, you lost 50 bucks".
Man, look up Karma, you poor soul.
Please read and comprehend. I said if I came along after they had gone. If I do not witness the loss of the money, how can I return it?