Troopers

Live posting....

My mom and brother are booked on a AA reservation from LHR to PHL (BA 67) and then PHL to SFO (AA 756), flying business class. Flight from LHR was scheduled to land at 4:35pm, with the PHL to SFO flight departing at 6:38pm same day (today). BA67 arrived about an hour late, leaving about an hour to make the connection. I was tracking their flight so I knew the connection would be tight. My bro texted me saying tons of people at immigration and they may miss their flight.

So, I called AA, explained the situation and the agent was very helpful in looking to rebook them next day. Two first class seats were unavailable direct, or through LAX, DFW, etc, tonight or tomorrow. Agent was very helpful. Accommodations would be provided. As the agent looks into the system more, she discovers that BA, on their own, exchanged my bro and mom's tickets and put them on a Delta flight tomorrow morning. Meanwhile, my bro and elderly mom are racing to the gate to catch the AA flight. Phone agent is unsure if the original AA ticket is valid or not. I'm waiting to hear back from my brother.

Phone agent provided me the Delta ticket number. I do see their flight on Delta tomorrow morning. Phone agent isn't sure who is responsible for the overnight accommodation since BA was late and exchanged their ticket on their own.

Update: they missed the AA flight.

Is AA or BA responsible for the accommodations?
Any other compensation warranted?