Delay due to loading luggage; missed connection
Hi all. Dad and sister are traveling today. Their SEA-SFO flight was delayed due to luggage still being loaded (according to father). UA.com shows "Airport conditions preventing departure" as the reason for the delay. The delay caused them to miss their onward connection. They originally had about an hour in SFO, but ended up arriving at the gate about 10 minutes before the scheduled departure time, and didn't make it to the departure gate until about 5 minutes prior.
UA auto-rebooked them on an AS itinerary tonight and a UA itinerary tomorrow. Because the delay was due to luggage, is UA obligated/expected to get them home as soon as possible regardless of carrier, or just when it's convenient for UA?