I think you are taking something said figuratively literally. Everyone has used "face the music" as an idiom to mean "take responsibility." I'll give her the benefit of doubt in this situation.
Since Snowden has taken responsibility, I don't see how you can construe was you said as anything other than a statement that Snowden should come back to the US and face prosecution for a capital offense.
That certainly isn't the same thing as calling for extra-legal assassination.
