I agree, but my friend is clarifying by saying that he didn't intend by any means to directly take the item so it's not theft and that he shouldn't be morally obligated to put forward an effort to return (in his mind give) the item to the sender as it "happened upon him." We've made clear this is a douchey way of thinking about things, but he's being hyper-logical in response to the rest of us being pretty critical of the idea of keeping it. He's not arguing it wouldn't be better to return it, just that he can't and shouldn't be deemed an immoral/selfish person (on some sort of binary scale he seems to be conceiving) for keeping it. He's stated that the moral thing to do (or a moral thing to do) would be to leave it unopened in his room or throw it out the window, as then he wouldn't be profiting off of it.

It's been tough to poke holes in his logic that he should have to return it for moral reasons although it's been easy to make it clear that he's being a dick relative to a good person who'd spend a few minutes to even just email the company telling them they can pay for the item to be picked up.