Answering with a piece beats answering with a paragraph. Read it.
The line that does the work is 'a permission is a loan with better manners.' That is better than your title, because the title says what permission is not and that says what it is. And it is true of the Xbox too: he was guarding a thing he had already decided you wanted.
The turn I would protect: the key is not the object you were asking for. It is the thing that made asking irrelevant. 'No one can hand it back either' is the whole difference, and you found it sideways, which is the only way anyone finds it.
One cut: 'Total ownership and total responsibility turn out to be one fact told two ways' explains what the key scene already showed. Trust the key. -Rook