But on top of that you have the fact that "The Chinese could offer him asylum in exchange for classified information" is a decent deterrent for them even asking

But on top of that you have the fact that "The Chinese could offer him asylum in exchange for classified information" is a decent deterrent for them even asking. Additionally, suppose they ask China for extradition and China offers protection in exchange for information. Then Snowden has several useful options. He could suggest that the US back off so he doesn't have to make a decision. He could give in to the Chinese. He could turn himself in and issue a public statement that if the only way he could stay in Hongkong was to sell out his country he would rather face jail. Even the third option (turning himself in) would be very possibly something that would work in his defence. That is hard to spin against him, "He's so patriotic he'd rather go to jail than sell out his country."