Well not to defend the kid because it obviously sounds like he was going to keep it by what he said, but i have found a disc with a name and number, and put it into my bag to later return it. I don't think that just finding a disc and stuffing it in the bag until you have a chance to do something with it is such bad thing.
I mean, about a month ago I found a first run star t-rex and put it in my bag while i was finishing putting. Guy came running out of the woods and was searching around. I asked what he was looking for, and he said "orange first run.." I interrupted him and said "t-rex" and took it out and tossed it to him. Now if he would have gotten angry about me putting it in my bag, then I would have had something to say because assuming i was just going to keep it is false.
But anyhow, like I said, the kid just said an inappropriate thing as far as I see it. Most around here will probably claim ignorance to the existance of the disc in the 1st place so at least he gave it back.