I don't understand what everyone is upset about. She said possibly. She didn't actually accuse the administration of acting this way, any more than Laura Bush was name calling when she said we were all possibly sexist yesterday. You are taking everything out of context.
Unless Couric thought the notion had credibility she would never have raised it. Sneaking in qualifiers like "possibly" or "some say" is nothing more than a technique Katie uses to give herself some cover when expressing her own opinions.
I'm guessing you didn't see the actual interview. If you had, I don't think you'd have any doubt that she was expressing her personal viewpoint and making a very serious accusation.