If IB refused to give you the option to repurchase the ticket using a different card and travel on the original flight, then I would blame IB, they had this capability as do all airlines. A lot of credit cards have a 3-digit code on the back which does not appear on the front of the card (on imprints taken from the card), and this is a security feature of the card. If the airline doesn't request this code when the ticket is paid for, the odds of needing the physical card is greatly increased. It may not be such a random process as the airport personnel think it is. This in turn ties into the credit card authorization and processing system that is used by the ticket issuer.