A good friend bought a ticket via Expedia back in August. The flight was apparently cancelled in September. He heard neither from expedia nor from the airline and only discovered that he had a useless ticket when he called to confirm the flight a week ago. Should he have been informed of the cancellation by the airline? Expedia? How could he prevent this in the future if he still wants to use Expedia?

I personally only buy direct from airlines or airline partners.