fastair

Oh, I accepted blame for the delay up to a point, and assessed blame beyond that outside of UA control to the company responsible for that part. Don't know how that is passing the buck. How could UA control the part that happened on another carrier as UA effectively (and contractually per the CoC) was only acting as an agent for them. Again, When one buys a ticket from an agent, they buy from them. Once a carrier accepts that ticket from the agent, they become their customer.

I guess the passenger could have not accepted the arrangement UA made with BA, and then could place a 24 hour blame on UA, but they didn't, they accepted UA's "outsourcing" of that segment. Hardly anything UA could do about it from that point. In fact, If BA had then had a cnclation for a mechanical, who do you think would have bought the room? Would BA say "All passenger's whose reservations and tickets are on us, but were bought on someone else, please return to that carrier. We ill take their money, and their passenger's but we won't take any of the risks involved." If the plane went down (god forbid, but it is an example) Would they say 150 souls onboard that bought tickets on us first hand, plus a few stragglers from other carriers? Would BA not pay the families of the survivors, but push that over to UA? That isn't the way things work. A carrier is responsible for travel on it's own metal, with a few minor exceptions for code sharing. Last I saw, UA does not code share, and therefore, (again, per the CoC) acts ONLY as an agent for the other carrier.

1st para in the CoC: A) THIS CONTRACT OF CARRIAGE SETS FORTH THE TERMS AND CONDITIONS ON WHICH UA PROVIDES AIR TRANSPORTATION TO PASSENGERS AND THEIR BAGGAGE ON FLIGHTS UA OPERATES, WHETHER SUCH AIR TRANSPORTATION IS PURCHASED FROM UA, ONE OF UA’S AGENTS OR FROM ANOTHER CARRIER. THE RULES CONTAINED IN THIS CONTRACT OF CARRIAGE ARE EXPRESSLY AGREED TO BY THE PASSENGER.

Same section, a few pages down: D) UA WILL BE RESPONSIBLE FOR THE FURNISHING OF TRANSPORTATION ONLY OVER ITS OWN LINES. WHEN UA UNDERTAKES TO ISSUE A TICKET, CHECK BAGGAGE, OR MAKE ANY OTHER ARRANGEMENTS FOR TRANSPORTATION OVER THE LINES OF ANY OTHER CARRIER (WHETHER OR NOT SUCH TRANSPORTATION IS PART OF A THROUGH SERVICE), UA WILL ACT ONLY AS AGENT FOR SUCH OTHER CARRIER, AND WILL ASSUME NO RESPONSIBILITY FOR THE ACTS OR OMISSIONS OF SUCH OTHER CARRIER.

Pretty straightforward, even BA takes responsibility as such:
2. When these conditions apply
2a) General

Except where clause 2c says otherwise, these conditions of carriage will apply to all flights we operate under the BA airline designator code and to any case where we have a legal liability to you in relation to your flight.

Seems that the buck is not being passed, but rather, the obligation was passed to BA.