Originally Posted by
jonsha
As written on the United website: United will transfer bags to a connecting flight on your United itinerary, or on a separate itinerary that includes a Star AllianceTM partner airline flight, if the connecting flight is scheduled to depart within 13 hours after arriving at the connection city.
According to this verbiage, UA was technically correct in denying you.
The UA flight was not on your itinerary, and the separate itinerary clause refers to partner airlines, not UA itself.