Does the AI just simply start with the ORS as a buildable unit?
It's the Covenant starter capital, like the Marathon and Phoenix are for the UNSC. They get one to start, and it can also be built from the start with extra command supply research.
I went and timed a game for myself. I used a tiny map with no Flood and set the AI to Reclaimer, just for good measure and to get the maximum amount of cheating. The first time I encountered the ORS was at minute 11; it was already level 5, had the refit research and was apparently ignoring colonizing altogether in favor of rushing my planets. It bypassed two planets entirely and blew straight to my capital, which it reached at minute 13. Exactly at minute 15, it fell to the combined fire of a Phoenix, two Marathons and over 20 frigates, admittedly having killed most of them and reached level 8 before the end.
In short, there definitely seems to be some voodoo nonsense going on with you. You're either the most unlucky person in the universe, or something went wrong with your download. That's all I can think of.