Originally Posted by Bukhara
Travel agent is responsible for servicing the booking. When the flight becomes 'unconfirmed' in their CRS, the agent is responsible for contacting the passenger. On most Expedia bookings, BA don't even have any contact details for the passenger as Expedia use Sabre (I think) and most of this info doesn't reach BA.
Even if contact details were available to BA, they will still leave the agent to do their job of servicing the booking and calling out the passenger.
Maybe as a matter of operational practice, but from a legal perspective, the contract for air transport is with BA, not the TA (which, as the name suggests, is just an
agent) and BA is legally responsible for the proper performance of the contract.