I had my PCs break into McNeil's jail and decided that Lone Star somehow ended up having an AI on the host as a security measure. I don't recall there is rule on how would the AI get on the host, but as it was a plot device I did not had to look at that.
However, one clear caveat appears while playing - the IA basically downgraded the host. So if you want a AI to be run on a host you have to make the AI attribute at least higher than the host rating, otherwise, the host is better on his own.