Actually, i read a fic a long time ago that had Galen wake up as his body was about to be discarded by stormtroopers. He killed them easily enough, put on the armor of one of them and proceeded to a nearby hangar where he stole a shuttle. The last scene of the story at that point had Galen crash the shuttle on an unknown planet due to an egine failure.
Also, i always thaught that Galen was merely on the brink of death at the end TFU?