Mueller can convict Stone without any involvement of Assange. Stone can’t force Assange to attend. He might make a motion to dismiss if Assange is not available to provide his defense, but the judge will probably deny it.
Mueller knows Assange knows the truth, and he’s taking this step believeing that Assange won’t be involved.
I think that whole aspect is moot; don't need to disprove a negative - the Mule didn't charge Stone over any alleged communications with WL or JA - the nature of the charge involved Stone trying to get access to other(s) that didn't have any real access either. Let's not forget that Stone is tied to Corsi and both are tied to Jones. Now Bannon is tied to Stone. The only connection that has not (cannot) be/been made is ties to WL or "Russia", etc.. These things rather always prove the opposite i.e. if there were any actual ties then these folks wouldn't have been trying to get access that they supposedly already had according to #FakeNews media. The absurdity is the libs + #FakeNews suggesting that there's more there - because if there was then there would have been no need to do the things that are alleged and then allegedly lying to try and cover up the fact there was no link(s) there.
