You're right that they don't have a bunch of obligations to stick by Snowden through legal challenges. Yes, it is ethically acceptable to publish public-interes

You're right that they don't have a bunch of obligations to stick by Snowden through legal challenges. Yes, it is ethically acceptable to publish public-interest excerpts from a source they believe is intrinsically illegal. They can also loudly have problems with the way he engaged with other media actors (a la publishing overly sensitive information) and still have a relationship with their source. Their contract with him is purely "do your best to mine and publish what you believe to be in the public interest from this trove of (possibly illegal) data". Simply put, you can say WaPo initially betrayed Snowden by (in their mind) publishing sensitive info (betrayal by incompetence). If their present thesis is correct, then they were intimately involved in increasing public harm from the leaks. At this juncture they had a number of options to make things right by their perception, but the one they chose was to attribute all blame to him (betrayal by deception). Not that Snowden had some special right not to be betrayed. He engaged with a lot of media actors, laid a lot of trust by their sense of journalistic ethics, and had to have accepted the risk of whatever fallout could happen from some of the outlets not acting in a trustworthy manner (mitigated by how selectively he involved people). That one of them "betrayed" him by not doing their job well, or pointing fingers at him is not really interesting. Again, I find the WaPo's dishonesty about their own role more interesting.