I wouldn't have thought that the GTA would have collected all the evidence and had enough time to analyse it, with most if not all of GTI involved in investigating the Shivan threat, and of course the rogue element designing and building Hades. After all, there would have presumably been many hours of interogation of not only Alex, but others allied with him, I would even wager that the Interpid's Admiral would have been questioned. So I'm inclined to agree with karajorma.
And Mr. Lobo, mutiny is a traitorous crime, punishable by death. Be very wary where you next make port...