Originally Posted by
WineCountryUA
This case seems different in the sense the outboard was successful --- so there must have been a ticket number generated.
What appears to have happened is a valid ticket was generated but the change was not properly handled by one of the carriers.
Good point. OP: was the outbound also on Asiana? If so, that would indicate that they had the reissued ticket in their system at some point, which would suggest that they never updated their system properly from the flight change. That would further imply that they never should have needed UA to make any changes; they should have been able to reconstruct the record and put the ticket number into it.