That is interesting. I'd suspect he could possibly be found guilty of attempted murder, and have the sentence reduced or eliminated by arguing that his previous sentence unjustly assumed guilt for this as well, and factored it into the sentence he already served.
If I remember correctly, there were comments from both the prosecution and judge that would basically prove that point- and they allowed evidence related to those other crimes in the trial. If they could prove this misconduct, they may even be able to argue double jeopardy.
There was deliberately no mention of the alleged murders-for-hire during the trial.
The judge said during sentencing that she was giving Ulbricht an incredibly harsh sentence to make an example of him to others who think that facilitating selling drugs is a victimless crime, and she was also angry at the huge stack of nice letters that people sent to the court in support of Ulbricht.