Flynn is the subject of a criminal investigation by the FBI. That helps in some cases, but even an investigation is not absolutely necessary for an obstruction of justice case. If you can obstruct justice and stop an investigation, then you will never have a crime because the investigation has been stopped. I am also amazed by all the leaks also. A lot have come from someone in the Whitehouse because only they have the information to leak and two staffers were named. The Far Right news has McMaster, Cohn, and Mattis as leakers and Cohn has been overheard leaking to reporters. But as to the other leaks not sure-- sometimes that's are described as sources and at other times as Officers of you name the agency. I think the Special Counsel will clamp down on this.