There are not any 'official' texts that examine the affair, no. There were not any impartial judges like we have today. We do have many texts concerning the affair, and they all give one of two explanations. The first, which I guess you could call the official story from the emperor's perspective, was that Stilicho was power-hungry and hoped to see his son appointed as emperor in the east. This is why the western emperor Honorius sanctioned his death. This story is somewhat believable - Stilicho was an ambitious man that had risen through the ranks and it was very common for powerful Romans to try to see their sons into powerful positions. Yet Stilicho was very loyal, having diligently fought against Rome's enemies. At one point he had Alaric's army cornered and was ready to pounce to utterly destroy it, but the eastern emperor, Arcadius, ordered him to withdraw, and he did, despite the glory that would have come with disobeying. Thus this story is both believable and not.

The other line is that Stilicho fell afoul of court intrigues. Writers of this line believe Stilicho remained loyal and was not trying to establish a dynasty through his son, but he was so powerful and influential that others at the imperial court were envious. These men conspired against the general, and due to the nature of military command, Stilicho had to leave the emperor's presence to lead the armies. On the other hand, the courtiers had the emperor's ear all day and every day, and probably convinced him that Stilicho was conspiring for the eastern throne.

In the end, it is difficult to know with certainty, but these are the two main possibilities.