Understandable. Then how would you explain LAX to LHR -- 2 non-stops exist on that route, 1 by UA, and 1 by NZ (ANZ). United will never ever ever sell anyone a ticket operated by ANZ on that route, despite, codesharing the flight. I've tried on UA.com as well as the call center. Yes, I understand a UA operated flight exists on that route, but so does a UA codeshare.