Originally Posted by
SK AAR
The delayed luggage is a UA issue. UA was the carrier and failed to retrieve and load the luggage at LHR. BA has nothing to do with this. Ask for reimbursement from your travel insurance or UA.
It will be an interesting one if push comes to shove. Whether handing over a BA baggage tag from a cancelled flight and expecting UA to retrieve it constitutes checking in baggage with UA may be a moot point.
In probability I doubt that UA ever had a realistic chance of getting the baggage to the traveller on time, and I would thing it even more unlikely they will pay out (at least without a fight).