For a bit of a semantics nitpick: tried, not judged. Judged implies no possibility other than a guilty verdict.
Assuming he didn't inform his Terran superiors (and he could very well have done so):
1) The ship did not come to harm and was effectively impervious to the efforts of a small number of GEF fighters.
2) He convinced the cell to attack the UEF transport. He could even say this was what actually happened, if he didn't tell his superiors about the Pegasi 'going missing'.
3) The Vasudan admiral was one we might call a "hawk", and was actively looking for a way to get more involved in the war, and as such no false communication occurred. Assuming a species' entire population thinks the same way on all issues is a path that leads to madness.
That said, in the event of a trial, that speech would be awesome.